Climate Control Student Guide

CLIMATE
CONTROL (CC1)
MitsubishiAcademy.com
STUDENT GUIDE

Course
Guide
CC1
Student
Course Guide
Climate Control
Student Course Guide
DIAMONDPRO CERTIFIED
TECHNICAL TRAINING
Course Description
Mitsubishi vehicles are equipped with both automatic and manual
climate control systems. In order to diagnose these systems accurately,
technicians must master refrigeration basics, passenger compartment
air flow control, heating and air conditioning components, as well as
related control systems and devices.
A solid understanding of the principles and components presented
here will improve Mitsubishi technician Fixed Right the First Time
performance and thus, dealership CSI scores.

2Course Guide Mitsubishi Motors North America, Inc.
Climate Control Student Course Guide
Course
Guide
SAFETY IS YOUR RESPONSIBILITY
This section is for use by professional Mitsubishi Motors dealership service technicians. The
descriptions and procedures in this publication supplement existing service manuals, technical
service bulletins, and other documents provided by Mitsubishi Motors North America, Inc.
(MMNA). As a result, the use of these sources may be required to ensure a proper repair.
Within this section there are Notes, Cautions, and Warnings. These references provide guidance
to help you do your job efficiently and safely. The definitions for these terms are listed below.
NOTE
A Note exists to help you do your job more efficiently. A Note may also provide
additional information to help clarify a particular point or procedure.
CAUTION
A Caution alerts you to the possibility of damage to either tools, equipment, or
to the vehicle itself. A Caution recommends that a procedure must be done in
a certain way to avoid potential problems resulting from improper technique or
method.
WARNING
A Warning alerts you to the highest level of risk. Warnings inform you that a
procedure must be done in a particular way to minimize the chances of an accident
that could result in personal injury or even loss of life.
Note
Caution
!
When you see a Note, Caution, or Warning, be sure you understand the message before you
attempt to perform any part of a service procedure. Also keep in mind it is impossible for MMNA
to anticipate or evaluate every service situation a technician may encounter. For that reason, you
have the final responsibility for personal safety–yours and those working around you. Be sure to
always wear proper protective clothing and safety equipment, use the proper tools, and follow
the repair procedures as outlined in various service publications provided by MMNA.
No part of this publication may be reproduced, stored electronically, or transmitted in any form or
by any means without prior written approval from Mitsubishi Motors North America, Inc. MMNA
reserves the right to make changes in the descriptions, specifications, or procedures without
prior notice or obligation.
Copyright © 2014 Mitsubishi Motors North America, Inc.
Corporate Technical Training Department

3Course GuideMitsubishi Motors North America, Inc.
Course
Guide
COURSE DESCRIPTION
The course details the fundamentals of heating,
air conditioning, and ventilation systems and of
the associated components.
Asolidunderstandingofclimatecontrolprinciples
and components presented here will improve
technician Fixed-Right First-Time performance
and dealership CSI scores.
COURSE GOALS
• Apply the four phases of the refrigeration
cycle to principles of heat transfer and energy
conservation.
• Describe the various functions of the
Ventilation System along with the related
control devices.
• Describe the climate control components
used with the Mitsubishi vehicles along with
their functions and operations.
• Describe the Manual and Automatic control
systems used to manage passenger
compartment and Traction Battery
temperatures.
• Define technician safety responsibilities
associated with A/C service and R134a
handling.
• Demonstrate the effective use of diagnostic
and service equipment to identify causes of
A/C system malfunctions.
PREREQUISITES
Successful completion of the following courses
is required for enrollment in Climate Control.
Consult MitsubishiAcademy.com for details.
• Electrical Systems 1 (ES1 or ELFB or ES1W)
• MEDIC 2 (MED2)
• MEDIC 3 (ME3W)
• Scan Tool Viewer (STV or STV 2 or STV3)
• Basics of Climate Control (MACW)
Slide Course Guide-3a
Slide Course Guide-3b
Slide Course Guide-3c

Course
Guide
SCHEDULE • Prerequisite Review
• Heat Transfer Principles (55.00A)
• Ventilation Systems (55.01A)
• Climate Control Components (55.02A)
• Electronic Control Systems (55.03A)
• Day 1 Exam
• Service Equipment (55.04A)
• Diagnosis and Repair (55.05A)
• Day 2 Exam
DAY 1
DAY 2
SYMBOLS
Symbols are used throughout the course to aid in
navigating the sections.
The Student Guide includes the following elements.
• Prerequisite Review Questions (Front pocket)
• Name Tent (Front pocket)
• Day 1 and Day 2 Quizzes (Front pocket)
• Course Achievement Worksheet (Front pocket)
• Course Guide
• Section 55.00A - Heat Transfer Principles
• Section 55.01A - Ventilation System
• Section 55.02A - Climate Control Components
• Section 55.03A - Electronic Control Systems
• Section 55.04A - Service Equipment
• Section 55.05A - Diagnosis and Repair
CSI
Pay special attention to these details as
they help Diagnose Customer Concerns
correctly to Fix It Right The First Time.
Video Refer to the related video material for
additional information.
Reference Refer to the related reference publication
for additional information.
Activity Perform the related activity and answer the
related questions.
Feedback
Complete the Knowledge Check to verify
your understanding of the materials.
STUDENT GUIDE CONTENTS

Course
Guide
Take advantage of your time during this course
to get the most from it.
Make notes or drawings any place in the Student
Guide to help recall the details later.
One of the main goals of Mitsubishi Training
is to provide as much individual instruction as
possible. If you do not understand something
in the classroom or shop, ask your instructor to
clarify the point.
Hands-on activities offer the opportunity to work
as part of a team. Rotate your roles in the team
so that everyone has a chance to complete the
exercise. Only by actively participating will you
learn from the experience.
The training course is an opportunity to learn
successfully in a controlled environment under
the guidance of a trained instructor. Learn from
your mistakes, practice good safety habits, and
use equipment and vehicles properly. Have
a good experience here and return to your
dealership with confidence in your abilities as a
trained professional.
Because Mitsubishi technical training is
competency based, hands-on activities
comprise 60% of the student’s evaluation.
The instructor will observe and evaluate each
technician’s performance, offering assistance
when necessary.
Summaries and Knowledge Check questions
wrap up each course section. Technician
participation in these activities comprises an
additional 10% of the evaluation.
Daily exams contribute to the final 30% of the
evaluation.
SUGGESTIONS FOR
SUCCESSFUL COMPLETION
Spend the Time Wisely
Take Notes
Ask Questions
Teamwork
Learn From Your Mistakes
STUDENT EVALUATION
Skill & Diagnosis Sections
Summaries and Knowledge Checks
Written Exams

Course
Guide
Slide Numbers
Numbers at the lower right corner of each
slide aid in student guide navigation.
• Section number indicates the topic.
• Student Guide page number follows.
• Completing the identification is a lower
case letter indicating the position
on the slide on the page:
a = Top
b = Middle
c = Bottom
55.01A = Ventilation System
16 = Student Guide Page #
a = Top of page
Slide 55.01A-16b
Segmented
Permanent
Magnet Rotor
Stator Windings
Electrical
Connector
Stator
Poles
Stator
Poles
STUDENT GUIDE NAVIGATION
Printed on the edge of each page are
section number tabs (for example,
55.02A as shown at right).
Page numbers are located on the
lower outside corner of each page (for
example, 55.02A 42 as shown at right).
Simply thumb through the pages to find a
specific page number.

Course
Guide
To ensure the information presented in the
prerequisite courses (ES1, MEDIC, STV, and
MACW) has been mastered, students will complete
the enclosed review questions. It does not count
toward the final score but is useful for reviewing
elements of electrical system basics, the use
of Mitsubishi’s scan tool, and technician ability
to research information using MEDIC. With the
previously completed courseware thoroughly in
mind, all students begin the Climate Control course
fully prepared.
PREREQUISITE REVIEW
COURSE ACHIEVEMENT
WORKSHEET
Climate Control 1
Technician Course Achievement Worksheet
Student Name: _________________________ Course Dates: _______________________________________
SKILL ACTIVITIES (60%) Possible Instructor’s Actual
Points Verification Points
Ventilation System Activities 10 _______ _____
Compressor Clutch Activities 10 _______ _____
Heated Seat Circuit Worksheets 10 _______ _____
Diagnosis Practice 30 _______ _____
Total 60 _______ _____
Instructor Comments:
QUIZZES (30%)
Day 1 Quiz (15 points possible) _______
Day 2 Quiz (15 points possible) _______
(30 points possible) _______
FINAL GRADE SUMMARY
(Minimum 80% = Passing Score)
Skill Activities (60 points) _______
Quizzes (30 Points) _______
Participation (10 points) _______
TOTAL _______
Mitsubishi Motors North America, Inc. 04/2014
Dealer Name: __________________________ Dealer Code: __________ Instructor: __________________

55.00A
TECHNICAL TRAINING
Heat Transfer Principles
Section Description
Diagnosing automotive climate control systems requires a thorough
understanding of energy conservation and heat transfer through the
four phases of the refrigeration cycle to move heat from the passenger
compartment to the outside air.
Theory Section
55.00A

1Section 55.00A Mitsubishi Motors North America, Inc.
Heat Transfer Principles55.00A
NOTE
CAUTION
method.
WARNING
Note
Caution
!

2Section 55.00AMitsubishi Motors North America, Inc.
Heat Transfers Principles
55.00A
Table of Contents
Section Introduction
Section Goal ………………………………………………………………...…… 3
Section Objectives ………………………………………………………………. 3
Needed Materials ……………………………………………………………….. 3
Time to Complete ……………………………………………………………….. 3
Automotive Climate Control ……………………………………………………………. 4
System Overview & Functions ………………………………………………… 4
Solid, Liquid, and Gas ………..……………………...…………………………………. 5
Kinetic Energy & Changing State: Adding or Removing Heat ……………………... 6
Heat Energy ……………….…………………………………………………………….. 7
Sensible Heat ……………………………………………………………………. 7
Measuring Heat …………………………………………………………………. 8
Heat Transfer ……………………………………………………………………. 8
Temperature …………………………………………………………………….. 9
Energy Conservation …………………………………………………………………… 11
Forms of Energy ………………………………………………………………… 11
Transferring Heat ……………………………………………………………….. 11
Heating System and Heater Core …………………………………………….. 12
Heat Transfer ……………………………………………………………………. 13
Radiation ………………………………………………………………………… 13
Conduction …………………………………………………………………….… 14
Convection …………………………………………………………………….… 15
Evaporation ……………………………………………………………………….15
Humidity & Comfort Zone ……………………………………………………… 16
Temperature and Pressure …………………………………………………………… 18
Heat Saturation & Engine Cooling……………………………………………. 19
Refrigeration Cycle …………………………………………………………………….. 20
Compressor ……………………………………………………………………… 21
Condenser ………………………………………………………………………. 22
Receiver-Drier …………………………………………………………………... 23
Thermostatic Expansion Valve (TXV) ………………………………………… 24
Fixed Orifice Tube (FOT) ………………………………………………………. 25
Accumulator ……………………………………………………………………… 25
Refrigerant Flow in a Fixed Orifice System ………………………………….. 26
Evaporator ……………………………………………………………………….. 27
Refrigeration Cycle Review ……………………………………………………. 28
Demonstration …………………………………………………………………… 29
Section Summary ……………………………………………………………………….. 31
Knowledge Review Questions ………………………………………………………… 33

SECTION GOAL
SECTION OBJECTIVES After completing this section, you will be able to
perform the following tasks.
• Identify the basic principles of energy
conservation and heat transfer.
• Identify when refrigerant is in a liquid or
gaseous state.
• Identify the points in the refrigeration cycle
when refrigerant is a liquid or gas
• Identify the points in the refrigeration cycle
when refrigerant is at low and high pressure
• Identify what type of heat transfer occurs when
refrigerant changes states under different
temperatures and pressures.
• Identify and explain the operation of system
components involved in the refrigeration cycle.
NEEDED MATERIALS
TIME TO COMPLETE
Section 55.00A only.
About 45 minutes
Slide 55.00A-3a
Slide 55.00A-3b
Apply the four phases of the refrigeration cycle
to the principles of heat transfer and energy
conservation.

55.00A
AUTOMOTIVE CLIMATE CONTROL
Automotive air conditioning has been used for over
seventy five years, providing passenger comfort
and convenience adding to pleasurable driving
experiences. Today, it is standard equipment in
virtually every car and truck sold in North America.
The functions of an automotive climate control
system are listed below.
• Provide heated or cooled and filtered air to the
passenger compartment.
• Dehumidify air directed to the windshield.
• Clear side windows for increased visibility.
• Circulate fresh or recirculated air to the
Slide 55.00A-4a
SYSTEM OVERVIEW
High Pressure Vapor
Low Pressure Vapor
High Pressure Liquid
Low Pressure Liquid
Heat absorbed from
passenger compartment
Pressure drops
to cool refrigerant
Heat released to atmosphere
Pressure
increase
to superheat
refrigerant
Slide 55.00A-4b
To achieve all of these functions, systems rely on
basic heat exchange principles to operate efficiently.
Road Surface
Exhaust
68°F
85°F
Engine
Transmission
Sunlight & Ambient
Sunlight & Ambient
Sunlight & Ambient

SOLID, LIQUID, or GAS While discussing a refrigeration system, it is
necessary to understand of how gases, liquids, and
solids behave under various conditions. All matter,
whether solid, liquid, or gas consist of billions of
molecules. Molecules are formed when atoms
come together to share electrons.
Molecular
Motion:
LIQUID
Slide 55.00A-5a
Slide 55.00A-5b
Molecular
Motion:
SOLID
In solid form, the electrons have insufficient energy
and tend to remain close together. This causes the
atoms within each molecule to stay close together
and in turn molecules exert a mutual attraction to
each other. This attraction is called cohesion.
In the liquid form, the electrons have more energy
and the distance between them increases. Distance
between atoms and molecules increase, causing
them to become less cohesive.
Molecular
Motion:
GAS
As a gas, molecules have very little attraction to one
another (or very low cohesion).
Slide 55.00A-5c
Solid
Liquid
Gas

Removingheatreduceskineticenergy
Addingheatincreaseskineticenergy
55.00A
KINETIC ENERGY Whether solid, liquid or gas the molecules in a
substance are constantly in motion. The colder
the substance, the less the molecules move.
The motion of the molecules increases as the
temperature increases.
The movement of molecules within matter is called
kinetic energy, or energy of motion. A temperature
reading is a measurement of the amount of kinetic
energy of the molecules.
CHANGING STATE:
ADDING OR REMOVING HEAT
When enough heat energy is removed from (or
added to) a substance, a change of state occurs.
Removing heat reduces kinetic energy and causes
molecular movement to slow down: gases become
liquids and liquids become solids.
Adding heat increases kinetic energy and causes
the molecular movement to speed up: solids
become liquids and liquids become gases.
Slide 55.00A-6a

There are two types of heat energy:
• Sensible Heat
• Latent Heat.
HEAT ENERGY
Sensible Heat
Sensible Heat is any heat that can be felt (or sensed)
and measured with a thermometer.
Slide 55.00A-7a
Temperature
Slide 55.00A-7b
Temperature is a measurement of the amount of
heat energy absorbed and retained by matter. Some
things feel hot, while others feel cold, but regardless
of whether it feels hot or cold, everything has some
degree of heat. A change in temperature is an
indication of a change in the amount of heat energy
being absorbed or released. Temperature can be
measured in either Celsius (º C) or Fahrenheit (º F).

55.00A
Measuring Heat
1 calorie raises 2.2 lbs. of H20 1.8ºF
1 BTU raises 1 lb. of H20 1ºF
1 kW = 3412.142 BTU/hr
Heat is measured in calories, British Thermal Units
(BTU), and kilowatts.
• One calorie is the amount of heat required to
raise 2.2 pounds of water 1.8º F.
• One BTU is the amount of heat required to raise
1 pound of water 1º F. (1 calorie = 1.22 BTU).
• One kW = 3412.142 BTU/hr
Note: The total heating and cooling capabilities of
many Mitsubishi climate control systems are often
listed in kilowatts.
Slide 55.00A-8a
Heat Transfer
Some form of energy is required to generate the heat
which causes the change in temperature. Energy,
in the form of heat, is transferred from one object to
another to cause the change in temperatures. Thus,
temperature is the measurement of the amount of
heat energy stored, released and absorbed during
the transfer.
Slide 55.00A-8b

Latent Heat
Latent Heat is unseen, or hidden. Latent heat is the
additional heat required to change matter from a
solid to a liquid or from a liquid to a gas. It is the
energy needed to break the cohesive bonds that
hold the molecules in one particular state. (Think
of latent heat as a heat storage battery. Just as a
battery stores unseen electricity, latent heat stores
heat energy in cohesive bonds.)
Slide 55.00A-9a
Water
212ºF
Steam
212ºF
For example we know water boils at sea level at
212º F. When water boils, it changes into a gas
in the form of water vapor or steam. If we were to
measure the temperature of the steam, it would be
the same temperature as the boiling water (212º F).
Slide 55.00A-9b

55.00A
Unseen or “latent heat” is the additional heat
(energy) absorbed to excite the water molecules on
the surface to move faster than molecules in the
liquid and change state to steam.
Heat a pound of water at 32º F until it turns to steam.
The water absorbs 180 BTUs to reach its boiling
point of 212º F. When the water reaches 212º F,
it can’t be made any hotter by applying more heat
(sensible heat). By continuing to apply more heat,
the water changes to a gas without a change in
temperature.
An additional 970 BTUs must be applied to change
one pound of 212º F water into 212º F steam.
The opposite is also true when water changes from
gas to liquid. Energy in the form of “latent heat” is
removed from the gas to convert it into a liquid.
So, Sensible Heat refers to Temperature while
Latent Heat refers to Change-of-State Energy.

ENERGY CONSERVATION A basic law of physics states that energy cannot be
created or destroyed. It can only change forms. As
we have seen, all matter has kinetic energy (above
absolute zero).
Energy can take various forms.
• Kinetic Energy
• Thermal (Heat) Energy
• Chemical Energy
• Mechanical Energy
• Electrical Energy
• Radiation
Energy can be converted from one form to another.
The mechanical energy used by a driver to apply the
brakes on a car is used to do the work of forcing the
brake pads against the brake rotor. This changes
the kinetic energy of the rotating wheel to thermal
(heat) energy at the brake rotor and pads. The heat
energy at the brake pads and rotor is transferred to
the atmosphere and remains as heat energy.
Transferring Heat
Slide 55.00A-11a
Forms of Energy
Air conditioning systems transfer heat energy from
the passenger compartment (evaporator, A) to the
outside atmosphere (condenser, B) by using a
change of state inside the sealed refrigerant system
from liquid to gas and then back into a liquid.
A
B

55.00A
Heating System
The heating system uses the same principles of
heat transfer as the air conditioning system, but in
a somewhat different way.
The chemical energy stored in gasoline is released
when electrical energy from the ignition system
ignites the air-fuel mixture. The result is the thermal
energy caused from combustion.
Slide 55.00A-12a
Coolant transfers heat in the engine. The heat of
combustion is absorbed into the coolant and moved
to the heater core. As the temperature of the coolant
flowing through the heater core is greater than the
air passing over the heater core fins, the heat from
the coolant is passed to the incoming air.
Slide 55.00A-12b
Heater Core

Heat can be transferred from one object to another
through four natural processes:
• Radiation
• Conduction
• Convection
• Evaporation
Heat Transfer
Slide 55.00A-13b
Slide 55.00A-13a
Hot Cool
Heat always moves from a warmer object
to a cooler object until both are at the same
temperature. This is the #1 principle involved in
climate control systems. Nature always seeks a
balance. Whenever a difference in temperature
or pressure exists, natural laws will tend to move
them back to equilibrium as much as possible.
Radiation is the movement of heat by particles,
waves, or rays. Radiation does not require air to
transfer heat.
Radiation
Road Surface
Exhaust
68°F
85°F
Engine
Transmission
Sunlight & Ambient
Sunlight & Ambient
Sunlight & Ambient

Conduction is the indirect transfer of heat through
a conductive material. The car’s radiator is an
example of conductive heat transfer.
Conduction
55.00A
Slide 55.00A-14a
Slide 55.00A-14b
The metal of the radiator conducts the heat from the
coolant to the air that passes over the radiator. It is
a conductive transfer because the coolant, which is
hot, never comes in contact with the outside air that
absorbs the heat.
Insulation is used to reduce conduction. Insulation
materials have millions of small air pockets. Air
does not readily conduct heat without the presence
of moisture. Insulation resists the heat outside from
conducting (through the metal of the vehicle) into
the passenger compartment.
Note

Convection There are two components of convection:
• Heat Exchange
• Circulatory Motion
Slide 55.00A-15a
HEAT
Cooler
air falls.
Warmer
air rises
As air is heated, it rises. As it cools, it falls. This
causes a circulatory motion that continues the heat
transfer process.
Glass
Steam
212°
970 BTU’s
Liquid
Liquid
Vapor
1 lbs.
Evaporation is the process where a liquid absorbs
heat and is transformed into vapor. As moisture
evaporates from a warm surface, it removes latent
heat and lowers the temperature of the surface. It
then releases the heat into the air and condenses
back into a liquid.
Evaporation
Slide 55.00A-15b

55.00A
Slide 55.00A-16a
Humidity & Comfort Zone
Humidity is the amount of moisture contained in the
air. Relative humidity is the amount of moisture as
a percent of air’s capacity to absorb moisture.
Humidity plays an important role in the ability of the
human body to maintain a comfort zone. That
comfort zone is 65ºF (70% humidity) to 91ºF (10%
humidity). Temperatures and humidity levels outside
this range produce discomfort.
When the relative humidity is high, air is less able
to absorb moisture. As a result, heat radiated
from the body does not evaporate as readily and
appears as perspiration. Perspiration increases
passenger discomfort in an automobile as the body
temperature remains outside the comfort zone.
One of the primary functions of the air conditioning
system is to dehumidify the air in the passenger
compartment so excess heat from the passengers‘
bodies is readily transferred to the air inside the
Set
Temperature
91°F @
10% Humidity
65°F @
70% Humidity

Evaporator Drain
Slide 55.00A-17a
The air conditioning system removes moisture from
the air passing over the evaporator fins through
condensation. The moisture in the air condenses on
the evaporator fins where the cooler temperature
of the evaporator causes the moisture in the air to
change state from a vapor to a liquid. The water that
results from this change of state is directed out of
the vehicle through the evaporator case drain.
Removing the moisture in the incoming air makes
the transfer of heat from the passengers to the
air inside of the vehicle easier and maintains the
passengers’ comfort zone in the range of human
comfort.
Evaporator Drain Tube

55.00A
TEMPERATURE and PRESSURE
Slide 55.00A-18a
Pressure plays an important role in heat transfer
and represents the amount of force exerted by one
object upon the surface of another.
Gravity acts on the gases in the atmosphere and
results in an air pressure of 14.7 pounds per square
inch (psi) of atmospheric pressure at sea level.
Pressure and temperature are directly related. If an
enclosed space is heated, the pressure in that space
increases. Likewise, increasing the pressure of a
substance (by reducing the volume of the enclosed
space) will increase the temperature.
Pressure also has an affect on the temperature
at which a liquid will boil and change to a gas.
Atmospheric pressure at sea level requires a water
temperature of 212º F to overcome that pressure
and transform the liquid to a gas.
However, at 5,000 feet elevation, water boils at
about 203ºF.
Vacuum Boiling Vacuum Boiling
(in. Hg) Point (in. Hg) Point
29 76.62 7 198.87
28 99.93 6 200.96
27 114.22 5 202.25
26 124.77 4 204.85
25 133.22 3 206.7
24 140.31 2 208.5
23 146.45 1 210.25
22 151.87 0 lb.
21 156.75 (14.7 psi)
20 161.19 1 lb. 215.6
19 165.24 2 lb. 218.5
18 169.00 4 lb. 224.4
17 172.51 6 lb. 229.8
16 175.80 8 lb. 234.8
15 178.91 10 lb. 239.4
14 181.82 15 lb. 249.8
13 184.61 25 lb. 266.8
12 187.21 50 lb. 297.7
11 189.75 75 lb. 320.1
10 192.19 100 lb. 337.9
9 194.50 125 lb. 352.9
8 196.73 200 lb. 387.9
Water Boiling Points at Various Pressures
212.0

Heat Saturation
Slide 55.00A-19a
Water boils when it contains all the heat it can for a
given pressure. If water at a lower pressure boils at
a lower temperature, it contains less heat than if it
boils at a higher pressure.
Engine Cooling
Automotive engine cooling systems use pressure to
transfer heat more effectively.
Each pound of pressure applied to a cooling system
raises the boiling point about 2.5ºF. A system
pressurized at 16 psi will not boil until about 250ºF at
sea level. The system continues to absorb heat up
to a higher temperature without turning into steam.
Pressure increases the amount of heat transfer
taking place.
Slide 55.00A-19b

55.00A
REFRIGERATION CYCLE
Slide 55.00A-20a
High Pressure Vapor
Low Pressure Vapor
Low Pressure Liquid
Heat absorbed from
passenger compartment
Pressure drops
to cool refrigerant
Heat released to atmosphere
Pressure
increase
to superheat
refrigerant
Air conditioning systems use the principles of heat,
temperature, and pressure to move heat from the
passenger compartment to the outside air.
The refrigeration cycle changes the refrigerant from
a gas to a liquid and then back into a gas, dropping
pressure to absorb heat, and increasing pressure
to release heat.
Any time there is a change in pressure, there is
a change in temperature. During these pressure-
temperature changes, there will also be a change
of state from liquid to gas or gas to liquid.

Compressor
The compressor is the heart of the air conditioning
system. It is the pump that converts mechanical
energy into heat energy.
Slide 55.00A-21a
Compressor
35 psi160 psi
Slide 55.00A-21b
The compressor draws low-pressure gas from a
Thermostatic Expansion Valve (or Fixed Orifice)
through the evaporator and into the suction side of
the compressor. The compressor pressurizes the
refrigerant, which also raises the temperature, and
discharges the superheated gas from the outlet
side as a high-temperature, high-pressure gas.

55.00A
Condenser
Slide 55.00A-22a
Refrigerant gas exits the compressor and flows to
the condenser located in front of the radiator.
Parallel Flow Condensor
Slide 55.00A-22b
Superheated gas from the compressor enters the
condenser passing through a series of coils. Since
the temperature of the coils is now higher than the
outside air passing over the coils, heat is transferred
to the atmosphere through conduction. To provide
maximum heat transfer, a fan is used to force air
over the condenser coils.

Receiver-Drier
Slide 55.00A-23a
As heat is transferred from the refrigerant to the
atmosphere, the refrigerant looses heat energy and
condenses from a high-pressure gas to a high-
pressure-liquid.
After leaving the condenser, the high-pressure,
liquid refrigerant flows into the receiver-drier.
Receiver-Drier
Slide 55.00A-23b
The receiver-drier is located between the condenser
and the evaporator, mounted next to, or integrated
with, the condenser as one component.
Strainer
Strainer
Desiccant

55.00A
Thermostatic Expansion Valve
(TXV)
Slide 55.00A-24a
The receiver-drier stores excess refrigerant and oil
to ensure a continuous supply. Receiver-driers also
contain a desiccant or drying agent to purify the
refrigerant. The refrigerant flow design also helps
trap debris at the bottom.
The high-pressure liquid from the compressor is
metered through the Thermal Expansion Valve
(TXV) to provide the necessary amount of refrigerant
to cool the interior of the car. It is housed inside
the evaporator housing, mounted to the evaporator.
The TXV is the system component located between
the receiver-drier and the evaporator.
The TXV is a variable restriction. Restrictions drop
pressure and thus temperature. The high-pressure
liquid is turned into a low-pressure, low-temperature
liquid mist as it is forced through the metering device
and on through the evaporator. The TXV varies the
amount of restriction to control the corresponding
pressure and temperature drop.
Slide 55.00A-24b

Fixed Orifice Tube
(FOT)
Fine Mesh
Filter Inlet
From
Condenser
Low Pressure Liquid
“O” Rings
Fine Mesh
Filter Outlet
To
Evaporator
Fixed Small
Diameter Bronze
Tube (Restriction)
2006-2009 Mitsubishi Raider uses a Fixed Orifice
Tube system. Like the TXV, the fixed orifice
provides a restriction to refrigerant flow to the
evaporator, causing the refrigerant to change from
high-pressure liguid to a low-pressure liquid mist.
The rate of flow depends on the pressure difference
across the restriction. Because the restriction is a
fixed size, system operation depends upon proper
compressor cycle times to function correctly.
Fine gauze filters are located at the inlet and outlet
sides of the orifice tube to prevent contaminates
from passing onto the evaporator.
Slide 55.00A-25a
Accumulator
Vapor Pick Up Tube
From Evaporator
(Low-Pressure
Liquid or Vapor)
To Compressor
(Low-Pressure Vapor)
Desiccant
Liquid
Slide 55.00A-25b
Located between the evaporator and compressor,
the accumulator stores refrigerant, filters particles,
absorbs moisture, and separates gaseous
refrigerant from liquid refrigerant.

55.00A
High Pressure Vapor
Low Pressure Vapor
Low Pressure Liquid
Fixed Orifice Tube
Accumulator
Slide 55.00A-26a
Refrigerant Flow in a
Fixed Orifice System
In a fixed orifice system, refrigerant leaves the
evaporator as a mixture of vapor and/or liquid. This
mixture enters the accumulator and falls to the
bottom. The vapor rises to the top and continues
onto compressor. Liquid refrigerant in the bottom of
the accumulator gradually vaporizes and is pulled
into the compressor.
From the compressor, high-pressure refrigerant
flows to the condenser. High-pressure liquid
refrigerant exits the condenser and flows to the
orifice tube where it changes to a low-pressure mist
entering the evaporator. The process then repeats.
The presence of an accumulator identifies the
system as Fixed Orifice versus TXV which uses a
receiver drier.
Also remember the accumulator is located on the
outlet side of the evaporator whereas the receiver
drier is located on the outlet side of the condenser.

Slide 54.56A-19a
Slide 55.00A-27a
Evaporator
The evaporator absorbs heat from the passenger
compartment and transfers it to the condenser
(through the refrigerant) which releases the heat to
the atmosphere.
Slide 55.00A-27b
Evaporator

55.00A
Air from inside the vehicle is blown over the fins
of the evaporator. Passenger compartment heat is
transferred to the low-pressure, low-temperature
refrigerant passing through the coils. As the
refrigerant absorbs heat, it changes state to a low-
pressure gas. The gaseous refrigerant is drawn
from the evaporator outlet into the suction side of
the compressor in a TXV system.
High Pressure Vapor
Low Pressure Vapor
Low Pressure Liquid
Plate and Fin Evaporator
Parallel Flow Condensor
Compressor
Sensing Bulb-Type
Thermostatic Expansion
Valve
Receiver/Dryer
Refrigeration Cycle Review
Slide 55.00A-28a

This activity reviews the refrigeration cycle and
demonstrates normal line temperatures and
pressures.
Before starting the engine, use MEDIC to locate
the Heater, Air Conditioning & Ventilation (Group
55A) for the assigned vehicle.
1. On what page does the Performance Test
procedure begin? _______________________
2. Complete the following Test Condition chart.
gsnitteSmetI
Environmental
Condition
Measurement Location
erutarepmeT
ytidimuH
Vehicle Body
Condition
dooH
rooD
Air
Conditioning
Condition
Air Conditioning Switch
emuloVriA
Temperature Control
teltuOriA
Outside/Inside Air Selection
deepSenignE
noissimsnarT
3. Connect the manifold gauge set to the LOW
and HIGH side ports. Static pressure = ______
Start the engine and allow it to reach operating
temperature. Set the climate control system
according to the Test Condition chart.
4. Center Air Outlet Temperature: ________
5. Pressures: HIGH Side _____ LOW Side _____
6. Using the illustration on the next page, circle the
line temperatures as either hot or cold.
Activity

55.00A
Hot or Cold Hot or Cold
Hot or Cold

Automotive air conditioning systems rely on
the principles of energy conservation and heat
transfer to maintain the desired comfort zone in the
Matter is composed of molecules, which are in
constant motion at any temperature above absolute
zero. Molecular movement results in kinetic energy.
As heat energy is added to a solid, kinetic energy
increases and the molecules move faster.
When enough heat energy has been added the
solid changes state into a liquid. When enough
additional heat energy is added, the liquid changes
into a gas. Removing heat from a gas will cause it
to change state into a liquid, and removing more
heat will change it into a solid.
Temperature refers to sensible heat and can be felt
or measured. Latent heat is absorbed or released
to cause a change of state in matter.
Energy cannot be created or destroyed; it can
only change form. An air conditioning system uses
this principle to transfer heat from the passenger
compartment to the outside atmosphere. Similarly,
heat from engine coolant is transferred to the
Pressure and temperature are directly proportional.
Adding pressure to a substance raises the heat
saturation point, or the amount of heat that the
substance can absorb before changing state.
Pressurizing a hot gas superheats the gas making it
easier to remove its latent heat. Lowering pressure
decreases temperature allowing a gas to absorb
latent heat.
The heat transfer process is referred to as the
refrigerant cycle.
A compressor draws warm low-pressure vaporized
refrigerant from the evaporator and pressurizes it,
creating a high-temperature, high-pressure gas.
The gaseous refrigerant flows to the condenser.
HEAT TRANSFER PRINCIPLES
SUMMARY

55.00A
The condenser releases superheat from the
refrigerant to the atmosphere changing its state to
a high-temperature liquid. To aid the heat transfer,
an electric fan is used which blows air over the
condenser coils.
A TXV or fixed orifice tube is used to change
high-pressure liquid refrigerant flowing from the
condenser to a low-pressure, low-temperature
liquid mist entering the evaporator.
As the fan motor blows air across the evaporator
coils, passenger compartment heat is transferred
to the low-temperature refrigerant. After absorbing
the passenger compartment heat, the vaporized
refrigerant is drawn from the evaporator into the
suction side of the compressor.

Answerthefollowingquestionstoreviewthematerial
from this section. If you don’t know the answer, look
it up. If you answer a question incorrectly, read
the material covering the topic again until you fully
understand the information.
1. Adding heat reduces kinetic energy.
a. TRUE
b. FALSE
2. The transfer of heat through matter is called
a. radiation.
b. convection.
c. conduction.
d. condensation.
3. The movement of heat energy from the surface
of warmer materials to colder materials through
air is called
a. radiation.
b. convection.
c. conduction.
d. condensation.
4. The transfer of heat by the movement of
warmed gasses or liquids is called
a. radiation
b. convection
c. conduction
d. condensation.
5. Which of the following represents heat transfer
through a radiator?
a. radiation
b. convection
c. conduction
d. condensation
6. Which of the following represents heat transfer
through a condensor?
a. radiation
b. convection
c. conduction
d. condensation
KNOWLEDGE CHECK
Feedback

55.00A
7. What device increases the refrigerant’s
temperature and pressure?
a. condenser
b. evaporator
c. TXV or FOT
d. compressor
8. What device decreases the refrigerant’s
temperature and pressure?
a. condenser
b. evaporator
c. TXV or FOT
d. compressor
9. Refrigerant leaves the evaporator and flows to
the receiver-drier in a FOT system.
a. TRUE
b. FALSE
10. Latent heat refers to temperature and can be
measured with a thermomter.
a. TRUE
b. FALSE

55.01A
TECHNICAL TRAINING
Ventilation System
Section Description
The ventilation system routes filtered, heated, or cooled air into the
passenger compartment through a series of ducts and outlets to the
defroster, panel, and floor.
Theory Section
55.01A

Ventilation System55.01A
NOTE
CAUTION
method.
WARNING
Note
Caution
!

Ventilation System
55.01A
Table of Contents
Section Goal ………………………………………………………………...…… 3
Time to Complete ……………………………………………………………….. 3
Ventilation System Functions ………….……………………………………………… 4
Blower Motor …………………..……………………...…………………………………. 5
Blower Motor Speed ……………………………………………..……………………... 6
Cabin Air Filter …………….…………………………………………………………….. 9
Air Dampers
Single Zone ……………………………………..……………………………….. 9
Dual Zone ……………………………………………………………………….. 11
Mode Film ………………………………………………….…………………….. 12
Air Damper Motors
Bidirectional DC Motor …………………………………………………………. 15
Stepper Motor …………………………………………………………………… 16
Endeavor Rear Blower …………………………………………………………………. 19
Raider Truck ……………………………………………………….……………………. 20
Ventilation System Odor Treatment ……………………………………………………21
Air Exit …………………………………………….……………………………………… 21
Ventilation System Shop Activities ……………………………………………………. 22
Ventilation System Summary ……………….…………………….…………………… 30

SECTION GOAL
SECTION OBJECTIVES After completing this section, you will be able to
perform the following tasks.
• Identify ventilation system functions.
• Describe blower operation and controls.
• Describe Single and Dual Zone systems.
• Describe Mode Film Damper operation.
• Identify damper motor designs and describe
the operations of each type.
NEEDED MATERIALS
TIME TO COMPLETE
About 30 minutes
Slide 55.01A-3a
Slide 55.01A-3b
Describe the various functions of the Ventilation
System along with the related control devices.

Ventilation System
55.01A
The ventilation system routes filtered, heated, and
cooled air into the passenger compartment through
a series of ducts and outlets.
Slide 55.01A-4b
VENTILATION
SYSTEM
Slide 55.01A-4a
Functions of the ventilation system.
• Bring outside air into the vehicle
• Recirculate interior air
• Circulate air through evaporator to remove heat
• Circulate air through heater core to add heat
• Direct air to floor, face, and defrost registers

Blower Motor
The blower motor forces air through the evaporator
and/or the heater core and out the registers.
Slide 55.01A-5a
Through a small tube, air is directed to the blower
motor from the heater case to cool the motor during
operation.
Slide 55.01A-5b

Ventilation System
55.01A
Power Transistor Cooling
Slide 55.01A-6a
Blower Motor Speed
Mitsubishi vehicles use either a power transistor or
a stepped resistor to control blower speed.
Battery voltage is supplied to the blower from the
blower motor relay housed in the ETACS-ECU (or
the Raider’s Integrated Power Module). The power
transistor or stepped resistor varies the current on
the motor’s ground circuit to change blower speed.
Thermal limiters (fuses) are used with both power
transistors and stepped resistors to protect the
blower circuit when temperatures climb due to
excessive current draw.
Thermal
Limiter
Power Transistor Stepped Resistor
Heat
Sink
Slide 55.01A-6b
To help keep it cool, a heat sink is used with a
power transistor to conduct heat to the surrounding
air. As in this Lancer example, the power transistor
is mounted at the bottom of the heater case and
exposed to cooling air flow from the fan.

Blower Motor Speed Control - Power Transistor (Lancer Sportback)
Slide 55.01A-7a

Ventilation System
55.01A
Blower Speed Control - Stepped Resistor (Eclipse)
Slide 55.01A-8a
FUSIBLE
LINK 1
BLOWER
MOTOR
BLOWER
SWITCH
RESISTOR

Cabin Air Filter
Air Dampers (Single Zone)
Slide 55.01A-9a
Also known as an air purifier, clean air filter, or pollen
filter, the element accomplishes these functions.
• Traps particles, pollen, mold, and spores
• Reduces unpleasant odors
• Improves A/C and heater performance
The filter element should be inspected and replaced
at regular intervals as indicated in the Mitsubishi
maintenance manual.
Air Mix Damper
Heater Core
Evaporator
Mode Damper
Outside/Inside
Air Damper
Intake Duct
Cabin Air Filter
Slide 55.01A-9b

Ventilation System
55.01A
Dampers are used to control air flow based on input
from the controller. Dampers on some older vehicles
were controlled directly by cables or by vacuum
controlled actuators. Currently, Mitsubishi vehicles
use electric motors to position the dampers.
Slide 55.01A-10a
Heater Core
Evaporator
Heater Outlet
Recirculation
Fresh
Cabin Air Filter
Outside/Inside
Air Damper
Mode Damper
To Panel Vents
To Defroster Vents
Air Mix Damper
After flowing through the evaporator, air can be
directed to the heater core by the Air Mix Damper
if a warm temperature is selected by the driver. The
damper can be positioned to provide full heat (all
air is directed to the heater core), full cool (all air is
blocked from flowing to the heater core) or a position
between the two allowing a blended temperature.
Depending upon its position, the Mode Damper
directs airflow to the panel registers, defrost vents,
or floor ducts.
The Outside/Inside Damper is opened to allow
fresh air into the vehicle or closed to recirculate
existing passenger compartment air.

Air Dampers (Dual Zone)
Some Mitsubishi vehicles are equipped with a
Dual Zone system where the driver’s side and
passenger’s side temperatures are controlled
independently.
A separator plate is installed in the case between
the evaporator and heater core. Individual air mix
dampers control the temperature to the driver (LH)
and passenger (RH) sides. Note in the illustration
above, the mode dampers are split to allow
movement over the separator plate.
Slide 55.01A-11a
Slide 55.01A-11b
Air Mix Damper (LH)
Heater core
Evaporator
Mode Damper
Outside/Inside
Air Damper
Clean Air Filter
Air Mix Damper (RH)
Separator Plate

Ventilation System
55.01A
Mode Film Damper
A bidirectional electric motor rotates the Mode Film
Damper to direct air to the defroster vents, panel
vents, and floor outlets.
Outside/Inside
Air Damper
Mode Damper
(Mode Film Damper)
MAX A/C Damper
Air Mix Damper
Heater Core
Evaporator
Slide 55.01A-12a
Eclipse, Endeavor, and Galant vehicles use a Mode
Film Damper to control airflow through the case.
Blower Motor
(Mode Film Damper)
Mode Damper
MAX A/C
Damper
Air Mix
Damper
Outside/Inside
Air Damper
Recirculation Fresh
Heater Outlet
Defroster Vents
Panel Vents
Heater Core
Evaporator
Flow Rate
Control Valve
Slide 55.01A-12b

Air through
Heater Core
To Air Outlets
Slide 55.01A-13a
After flowing through the heater core, air is directed
into the Mode Film Damper and exits through the
vents as shown above. However, if the driver
selects PANEL, airflow from the heater core is
directed through the small center opening and exits
at the bottom of the damper. See PANEL VENTS
ONLY in the illustration below.
PANELPANEL
FLOOR
DEFROST
DEFROST
FLOOR
FLOOR
PANEL VENTS ONLY
DEFROST VENTS ONLY
FLOOR OUTLETS ONLYPANEL AND FLOOR
DEFROST AND FLOOR
MAX A/C
Damper
Air Mix
Damper
In all positions except PANEL VENTS ONLY, both
the MAX A/C and Air Mix dampers close to force all
air to flow through the heater core.
Slide 55.01A-13b

Ventilation System
55.01A
To improve air conditioner performance with a
system using a Mode Film Damper, a Flow Rate
Control Valve is used to regulate coolant flow into
the heater core. Coolant is blocked from flowing to
the heater core when the driver selects maximum
A/C preventing the cooled air from being reheated.
Note: the Air Mix Damper motor also regulates the
Flow Rate Control Valve.
Flow Rate Control Valve
From Engine
Return to Engine
Air Mix Damper
regulates coolant flow
Coolant Bypass
Slide 55.01A-14b
Slide 55.01A-14a
Note the center shaft position when the motor drives
the Mode Film Damper to panel vents or defrost
vents (maximum travel positions).
Panel Vents Only
Defrost Vents Only

Slide 55.01A-15a
MODE SELECTION
DAMPER CONTROL
MOTOR AND POTENTIOMETER
AIR
THERMO
SENSOR
MOTOR
DRIVE
CIRCUIT
JOINT
CONNECTOR (2)
JOINT
CONNECTOR
(2)
AIR MIXING
DAMPER CONTROL
MOTOR AND
POTENSIOMETER
INTERIOR
TEMPERA-
TURE
SENSOR
JOINT
CONNECTOR
(2)
Electric motors position the Outside/Inside, Mode,
and Air Mix dampers.
Some Mitsubishi vehicles use a potentiometer
incorporated in the bidirectional motor assembly to
determine damper position. (Wiring schematic of
an Endeavor is shown below as an example.)
Air Damper Motors
Bidirectional DC Motor

Ventilation System
55.01A
Many current Mitsubishi vehicles use stepper
motors to control the Outside/Inside, Air Mix, and
Mode damper positions.
Stepper Motor
Slide 55.01A-16b
Mode
Damper Motor
Outside/Inside
Damper Motor
Air Mix
Damper Motor
Slide 55.01A-16a
A stepper motor is a brushless DC electric motor
that divides one full rotation into multiple equal
steps. The motor’s position is commanded to move
and hold at one of these steps without the need of
a feedback sensor.
The permanent magnet rotor is constructed with
alternating north and south poles arranged parallel
to the rotor shaft.
Segmented
Permanent
Magnet Rotor
Stator Windings
Electrical
Connector
Stator
Poles
Stator
Poles

Four sets of stator poles are arranged around the
two stator windings. One set of poles is mounted
above each winding and one set below.
Using NPN transistors, the controller alternately
energizes the two stator windings to magnetize the
poles which attract or repel the rotor’s permanent
magnets in sequential steps.
Diodes are used to eliminate current spikes when
each stator is de-energized.
When reviewing Data List items, remember any %
displayed on the scan tool represents a calculation
of damper position only and not a direct feedback.
Slide 55.01A-17a
NN N
N N
N
S
N
S
S S
SS
Stator Pole
Stator Winding
Note

Ventilation System
55.01A
Slide 55.01A-18a
MODE SELECTION
DAMPER CONTROL MOTOR
AIR MIXING
OUTSIDE/INSIDE AIR SELECTION
12V
A/C CONTROL UNIT
Slide 55.01A-18b
The pattern above illustrates the signal produced by
the A/C-ECU to move the rotor in individual steps.

Rear Blower Motor
Rear Blower Unit
Rear Blower
Resistor
Rear Blower Speed Control
Endeavor Rear Blower Unit
Slide 55.01A-19a
The Endeavor uses a rear blower unit installed in
the center console for back seat passengers.
When the front blower is ON and the Air Mode
Damper is set to PANEL or PANEL/FLOOR, the
rear blower can be operated.
Only the rear fan speed can be set. Rear outlet
temperature is set with the front controls.

Ventilation System
55.01A
Where other Mitsubishi systems use one Air Mode
damper to control air flow to the defroster, panel,
and floor, the Raider system uses two (9 and 11
shown in the drawing above). Other than this
exception, all air flow functions are the same.
1. Air to defrost
2. Heater core
3. Temperature blend damper
4. Fresh air entry
5. Outside/Inside damper
6. Recirculated air flow
7. Evaporator
8. Air to floor
9. Floor, panel, defroster damper
10. Air to panel vents
11. Panel, defrost damper
Heater Case - Raider Truck
Slide 55.01A-20a
1. Case
2. Heater core
3. Blend-air doors & actuator
4. Evaporator
5. Blower motor resistor
6. Recirc door and actuator
7. Blower motor
8. Evaporator temp sensor
9. Mode-air doors & actuator
Slide 55.01A-20B
Heater Case Air Flow - Raider Truck

Musty Odors from the
Climate Control System
Some customers may complain of an unpleasant
“musty” odor in the passenger compartment when
the fan blower is switched on. This condition occurs
more often in humid climates. Condensation on
the evaporator mixes with airborne pollutants and
substances. To temporarily eliminate these odors,
the evaporator can be treated with Mitsubishi
Cooling Coil Coating. Refer to TSB-02-55-005 for
more details.
Slide 55.01A-21a
Air Exit
To complete the ventilation system, a path for air to
exit the passenger compartment is provided at the
rear of the vehicle. (Mirage is shown below.)
Slide 55.01A-21b

Ventilation System
55.01A
VENTILATION SYSTEM - Outlander
NOTE: The results observed during this activity may
vary slightly depending on shop air temperature.
temperature. Press the AUTO button. Set both
driver & passenger temperatures to 89º F.
1. Is the compressor engaged? YES or NO
2. Where is the air flow directed?
Face
Floor
Floor/Face
Defrost
3. Number of blower speed bars displayed? ____
Decrease the driver side temperature to 88º F.
Decrease the driver side temperature to 87º F.
Continue to decrease driver temperature.
7. At what temperature does the air flow direction
change from floor to floor/face? ________ º F
Continue to decrease driver temperature.
change to face only? ____ º F
Continue to decrease driver side temperature.
9. At what temperature does the blower speed
begin to increase? ____ º F
10. At what temperature does the blower speed
increase to maximum (8 bars) ? ____ º F
Activity

Reset the driver side temperature to 89º F.
12. Number of blower speed bars displayed. ____
Face
Floor
Floor/Face
Defrost
Set the passenger side temperature to 88º F.
14. The system is now in _______ zone mode.
Decrease passenger side temperature to 87º F.
18. Decrease passenger side temperature to 61º F
and describe the system operation. ____________

Ventilation System
55.01A
VENTILATION SYSTEM - Mirage
NOTE: The results observed during this activity may
vary slightly depending on shop air temperature.
temperature. Press the AUTO button. Set the
temperature to 89º F.
Face
Floor
Floor/Face
Defrost
2. What is the air source? (Outside or Inside)
Decrease blower speed to 3 bars then press the
AUTO button and note the blower speed.
3. What happened to the blower speed? ________
Decrease the set temperature to 88º F.
4. Does the compressor engage? YES or NO
Reduce temperature to 75º F.
5. How many blower speed bars are displayed? ___
Continue to decrease set temperature.
change to floor/face? _____
change to face? _____
7. At what temperature does the Outside/Inside
damper change to recirculation? _____
Activity

7. At what temperature does blower speed begin
to increase? _____
Press the Defrost button.
8. What is the air source? Outside or Inside
9. Did blower speed or set temperature change?
YES or NO
Set the temperature to 85º F. Using the mode
button, set the air discharge to floor/defrost. Touch
Defrost button.
10. Where is air flow directed? _______________
11. When the Defrost button is pressed again,
where is the air flow directed? ________________
12. Touch OFF. Where is air source? __________

Ventilation System
55.01A
VENTILATION SYSTEM - Outlander Sport
In this activity, ventilation system components will
be activated with MUT-III.
temperature. Set the controls to max heat, high
blower speed, air discharge to face, and engage
the compressor. From System Select, click Air
Conditioner and click the Actuator Test button.
From the Actuator Test screen, click the Drop Down
Arrow and select #5 Inside/Outside Damper from
the list.
On the right side of the screen, click the Data List
(Text) button. Scroll through the items until #45 (In/
out select damp poten (target) and #46 (In/out
select damp potentiometer are displayed.
Set the Actuator Test to Recirc and click the check
mark to continue. List the results below.
1. #45 ____________________ (Recirc or Fresh)
2. #46 _______ % (list the full range)
3. Describe the blower sound when the damper is
fully closed. ____________________________
______________________________________
Click X at the bottom of the screen to exit the test
and confirm the damper returns to Fresh position.
On the control panel inside the vehicle, select
Recirculation position and enter the results below.
4. #45 ____________________ (Recirc or Fresh)
5. #46 _______ % (list the full range)
Click X at the bottom of the screen to exit the test.
Arrow and select #8 Air outlet c/o damper from
the list.
Activity

On the right side of the screen, scroll through the
list until #55 (Air outlet c/o potentiometer) is
displayed.
For each damper position selected during the
Actuator Test, record the percentage shown for the
Air outlet c/o potentiometer (data item #55).
6. Face ______ %
7. Bi-Level 1 ______ %
8. Bi-Level 2 ______ %
9. Bi-Level 3 ______ %
10. Foot ______ %
11. Def/Foot 1 ______ %
12. Def/Foot 2 ______ %
13. Def/Foot 3 ______ %
14. Defrost ______ %
Arrow and select #6 Air mix damper motor from
the list.
On the right side of the screen, scroll through the
list until #63 (Air mix potentiometer) is displayed.
15. Damper position for full heat ________ %
Set the #6 Air mix damper motor position to 0.
16. Damper position for full cool ________ %.
(Feel the air temperature at the face register.)
Set the system controls to max cool, blower OFF, air
discharge to floor, and disengage the compressor.
Shut the engine OFF.

Ventilation System
55.01A
VENTILATION SYSTEM - i-MiEV
Turn i-MiEV key to start position. (Ensure the
READY light is illuminated on instrument cluster.)
Rotate the temperature selection dial to full heat
and press PUSH MAX. Set high blower speed,
air discharge to face, and engage the compressor.
From System Select, click Air Conditioner and click
the Actuator Test button.
Arrow and select #4 MAX Switch Output from the
list.
(Text) button. Scroll through the items until #60
(MAX Switch Input) and #72 (MAX Switch Output)
are displayed.
Set MAX Switch Input to OFF and click the check
mark to continue. List the results below.
1. #60 _________
2. #72 _________
3. Describe the MAX Switch Light on the control
panel. ______ (ON or OFF)
4. #60 _________
5. #72 _________
6. Describe the MAX Switch Light on the control
panel. ______ (ON or OFF)
On the control panel inside the vehicle, set system
to OFF.
Arrow and select #7 Front Blower Fan from the list.
(Text) button. Scroll through the items until #68
(Front Blower Fan) is displayed.
Activity

For each blower speed selected during the
Actuator Test, record the voltage shown for the
Front Blower Fan (data item #68).
7. OFF _______ V
8. 1step _______ V
9. 2step _______ V
10 3step _______ V
11. 4step _______ V
12. 5step _______ V
13. 6step _______ V
14. 7step _______ V
15. 8step _______ V
16. MAX H _______ V
17. MAX C _______ V
Set temperature dial to 9:00 o’clock position,
blower OFF, air discharge to floor, and disengage
the compressor. Turn key to OFF (LOCK).

Ventilation System
55.01A
The ventilation system brings filtered outside air into
the vehicle directing it to the panel registers (face),
floor, and defrost vents. Dampers are used to
control air flow based on outputs from the controller.
After flowing through the evaporator, air can be
directed to the heater core by the Air Mix Damper if
a warm temperature is selected by the driver. The
damper can be positioned to provide full heat (all
air is directed to the heater core), full cool (all air is
blocked from flowing through the heater core) or a
position between the two for a blended temperature.
Depending upon its position, the Mode Damper
directs airflow to the panel registers, defrost vents,
and floor ducts.
The Outside/Inside Damper is opened to allow
outside air into the vehicle or closed to recirculate
existing passenger compartment air.
Bidirectional DC motors or stepper motors are used
to position the dampers.
A blower motor forces air through the evaporator
and/or the heater core and out the registers.
A power transistor or a stepped resistor is used
to control blower motor speed. Battery voltage is
supplied to the blower from the blower motor relay.
Based on signals from the controller, the power
transistor or stepped resistor varies the current
to change blower speed. To dissipate heat, these
components are exposed to cool air flowing within
the heater case.
Current Mitsubishi vehicles use a cabin air filter to
trap particles, pollen, mold, and spores. It reduces
unpleasant odors and improves A/C and heater
performance.
A vent is positioned at the rear of the vehicle to
allow air to exit the passenger compartment.
VENTILATION SYSTEM SUMMARY

Answer the following questions to review the
material in this section. If you don’t know the answer,
look it up. If you answer a question incorrectly,
read the material covering the topic again until fully
understand the information.
1. Blower speed is controlled by varying current
flowing to the motor with a stepped resistor or
power transistor.
a. TRUE
b. FALSE
2. The Dual Zone system allows the driver to
select a different fan speed than the
passenger.
a. TRUE
b. FALSE
3. To monitor damper position, some Mitsubishi
ventilation systems use what device?
a. thermistor
b. potentiometer
c. capacitor
d. fixed value resistor
4. What damper is used to direct air over the
heater core?
a. mode damper
b. air mix damper
c. outside/inside damper
d. None of these answers is correct.
5. Describe the cabin air filter.
a. traps particles and pollen
b. improves A/C and heater performance
c. should be replaced at regular intervals
d. All of these answers are correct.
6. If the mode damper is open, fresh air enters
the passenger compartment.
a. TRUE
b. FALSE
KNOWLEDGE CHECK
Feedback

Ventilation System
55.01A
7. Two technicians are discussing the operation
of a blower motor resistor. Technician A says
the thermal limiter protects the blower circuit
from excessive current draw and opens at
approximately 250ºF. Technician B says only
HI blower speed occurs if the thermal limiter
opens. Who is correct?
a. Technician A
b. Technician B
c. Both Technician A and B are correct.
d. Neither Technician A nor B is correct.
8. A stepper motor is capable of positioning a
damper in incremental steps.
a. TRUE
b. FALSE
9. The Flow Rate Control Valve is used when the
driver selects __________ .
a. Max A/C
b. Max heat
c. Panel/Floor
d. Floor
10. What device regulates the Flow Rate Control
Valve?
a. Mode Film Damper motor
b. Air Mix Damper motor
c. Max A/C Damper motor
d. Water Shut-off Valve Controller

55.02A
TECHNICAL TRAINING
Climate Control
Components
Section Description
Various heating and air conditioning components are used to control
passenger compartment temperature and humidity levels. This
section describes the individual elements used to heat and cool air
flowing into the vehicle.
Theory Section
To
Evaporator
55.02A

Climate Control Components55.02A
NOTE
CAUTION
method.
WARNING
Note
Caution
!

Climate Control Components
55.02A
Table of Contents
Section Goal ………………………………………………………………...…… 3
Time to Complete ……………………………………………………………….. 3
Refrigeration System Components
A/C Compressors ………………………………………………………………. 4
Belt Driven Scroll Compressor ………………………………………… 5
Electric Motor Driven Scroll Compressor …………………………….. 6
Swash Plate Compressor ……………………...………………………. 10
Rotary Vane Compressor ……………………………………………… 12
Compressor Clutch ……..………………………..…………………….. 13
Refrigerant Temperature Switch ……………………………………… 17
A/C Pressure Sensor …………………………………………………… 18
Pressure Relief Valve ………………….………………………………. 20
Fin Temperature Sensor ………………………………………………………. 20
Ambient Temperature Sensor …………………………………………………. 21
Interior Temperature Sensor and Aspirator ………………………………..… 23
Photo (Sunload) Sensor ……………………………………………………….. 25
Parallel-Flow Condenser ………………………………………………………. 26
Radiator and Condenser Fan Control ………………………………………… 27
Plate & Fin Laminated Evaporator ……………………………………………. 30
Thermal Expansion Valve (TXV) Operation …………………………………. 31
Capillary Tube TXV Operation …………………………...……………. 32
Block-type TXV Operation …………………………..……………….… 34
Refrigerant Lines ……………………………………………………………..… 35
Refrigerant Hoses ………………………………………………………………. 36
Charge Ports ……………………………………………………………………. 36
“O”-Rings …………………………………………………………………….….. 37
R134a Refrigerant …………………………………………………………….… 37
Refrigerant Oils …………………………………………………………………. 38
Heating System Components
Engine Cooling System ………………………………………………………… 40
Water Pump ……………………………………………………………………… 40
Thermostat ………………………………………………………………………. 41
Heater Core ……………………………………………………………………… 41
Radiator, Cooling Fan, and Radiator Cap ……………………………………. 42
Positive Temperature Coefficient (PTC) Coolant Heater (i-MiEV) ……….... 43
Electric Coolant Pump ……………………………………………………….…. 48
Positive Temperature Coefficient (PTC) Air Heater (Mirage) …………….… 49
Heated Seats ……………………………………………………………………..52
Climate Control Components Summary ……….…………………………………….. 55

SECTION GOAL
SECTION OBJECTIVES After completing this section, students will be able
to perform the following tasks.
• Identify A/C system components and describe
their operations.
• Identify heating system components and
describe their operations.
NEEDED MATERIALS
TIME TO COMPLETE
About 2 hours
Slide 55.02A-3a
Slide 55.02A-3b
Describe the climate control components
used with Mitsubishi vehicles along with their
functions, and operations.

55.02A
As discussed in the first section, theA/C compressor
draws in low-temperature, low-pressure refrigerant
from the evaporator. The compressor routes high-
temperature, high-pressure gas to the condenser.
Currently Mitsubishi uses three air conditioning
compressor designs depending on vehicle
application and system requirements. Each of these
compressor designs and their specific operation is
detailed in this section.
• Scroll compressor
• Swash Plate (Axial) compressor
• Rotary Vane compressor
REFRIGERATION SYSTEM
COMPONENTS
Slide 55.02A-4a
Compressor Designs:
- Scroll
- Swash Plate (axial)
- Rotary Vane
This section is divided into two parts:
• Refrigeration System Components
• Heating System Components.
A/C Compressors

Belt Driven
Scroll Compressor
Currently, the Scroll design is the most commonly
used compressor with Mitsubishi vehicles. The
Mitsubishi Heavy Industries (MHI) QS90 model is
shown above.
Slide 55.02A-5a
Slide 55.02A-5b
The compressor uses two scrolls; one stationary
and one movable. The movable scroll is connected
to the compressor shaft with a concentric and is
able to orbit. As the movable spiral oscillates within
the fixed spiral, a number of pockets are formed. As
these pockets decrease in size, the refrigerant is
pressurized and exits through a discharge valve in
the rear section of the compressor.
In most applications, the movable scroll is driven by
the engine’s crankshaft with a drive belt when the
compressor clutch is engaged.
Discharge
Valve
Orbiting Scroll
Fixed Scroll
Crankshaft
Clutch
Assembly

55.02A
Electric Motor Driven
Scroll Compressor.
Dampers
A/C Compressor Bracket
Chassis Ground
High Voltage Cable
12-V System
Wiring Harness
Inverter
Electric Motor
A/C Compressor
High Pressure Relief Valve
However, the moveable scroll in the compressor
used with the i-MiEV is driven with a high-voltage
AC (alternating current) electric motor and requires
no clutch. The compressor is mounted under the
car, forward of the Traction Battery adjacent to the
Electric Power Steering rack.
Slide 55.02A-6a
Unlike a conventional A/C system where pressures
are controlled by cycling the compressor clutch, the
electric motor varies the scroll speed to maintain
proper pressure.
Orbiting Scroll
Field Winding
Armature
Slide 55.02A-6b

Stationary
Scroll Seal
Obiting
Scroll Seal
Slide 55.02A-7b
Refrigerant &
POE flow passages
Internal passages allow the compressor to draw
refrigerant and oil through the stator windings to aid
in high voltage motor cooling and lubrication.
Slide 55.02A-7a
Seals are installed in grooves in the stationary and
orbiting scroll as shown above.

55.02A
Slide 55.02A-8b
The electric motor’s armature drives the concentric
causing the movable scroll to orbit.
Slide 55.02A-8a
High voltage DC (direct current) from the vehicle’s
Traction Battery is directed to the A/C compressor
inverter (shown above) which converts it to AC
(alternating current) to drive the electric motor.
Compressor Specifications:
• Displacement = 30cc
• Maximum Speed = 6,000 RPM
• Maximum Input Current = 20.5 A (at 220 VDC)
The i-MiEV A/C system is automatically engaged
during Level 3 (Quick) charging or whenever the
Traction Battery temperature exceeds 86º F.
Note

(FUSE )16
CASE
GROUND
A/C
CONTROL
UNIT
A/C
COMPRESSOR
MAIN CONTACTOR
HIGH
VOLTAGE
FUSE
RELAY BOX
TRACTION BATTERY
GROUNDING
CONNECTOR
INDICATES HIGH VOLTAGE CABLES,
WIRING HARNESSES, OR CONNECTORS.
Slide 55.02A-9a
Orange cables connect the A/C compressor to the
high voltage Traction Battery as shown above.
ALWAYS consult the appropriate Mitsubishi service
publications for proper procedures and important
precautions applicable to the high voltage system.!

55.02A
Slide 55.02A-10a
Swash Plate Compressor
A Swash Plate compressor (also called axial)
employs reciprocating pistons to compress the
refrigerant. The engine drives the compressor
crankshaft through a belt which drives the swash
plate. Mitsubishi Swash Plate compressors are all
multiple piston designs with ten pistons.
The 2006-2009 Raider uses the Denso 10S17E
Swash Plate design compressor, displacing 150 cc.
Piston
Swash PlateReed Valves
Clutch
Suction
Discharge
Reed Valves
Slide 55.02A-10b

Slide 55.02A-10a
The ten-cylinder swash plate compressor has five
bores, each having two piston faces, one on each
side of the wobble plate. The intake stroke on one
side is the compression stroke on the other side as
the pistons travel in the same bore. One complete
revolution of the swash plate drives the pistons
from one end of their travel to the other end and
back again.
As a piston begins its stroke from one end of the
cylinder, vacuum opens the intake reed valve and
draws refrigerant from the Low Side into the cylinder.
As the piston reverses direction and moves to the
opposite end of the cylinder, the intake reed valve
closes and the gas is compressed. When the gas
gains enough pressure, it forces the discharge reed
valve open allowing the charge to flow into the High
Side of the system. As the piston reverses travel
again, the discharge reed valve closes and the
cycle begins again.
Reed Valve Plates
Swash plate compressors use spring steel suction
and discharge reed valve plates in both the front
and rear cylinder heads. The spring tension in the
steel is controlled by the thickness of the steel and
is calibrated to control valve timing by the suction of
the piston during the intake stroke and pressure of
the charge on the discharge stroke. Timing of the
intake and compression charges is a function of the
opening and closing of the individual reed valves on
each of the plates.
Slide 55.02A-11a

55.02A
Rotary Vane Compressor
Slide 55.02A-12a
A Rotary Vane compressor, made by Valeo, is used
on Mirage beginning with the 2014 model year.
Slide 55.02A-12b
This compressor design consists of a rotor with two
vanes and a carefully shaped rotor housing. As the
compressor shaft rotates, the vanes and housing
form chambers. Refrigerant is drawn from the
suction port into these chambers, which diminish
in size as the rotor turns. The vanes are sealed
against the rotor housing by centrifugal force and
refrigerant oil.
Suction
Discharge
Vanes

A compressor clutch is a stationary field
electromagnetic device. The stationary field coil is
attached to the compressor body with bolts. The
pulley is retained with a bearing and snap ring. The
front plate is mounted to the compressor shaft and
held in place with a retaining nut.
When there is no current to the field coil, there is no
magnetic force applied to the clutch and the pulley
spins freely. The front plate and the compressor
shaft remain stationary.
When current is supplied to the field coil, magnetic
force pulls the front plate against the pulley and
both spin as one unit, turning the compressor shaft.
When the clutch is disengaged, small, flat steel
springs pull the front plate away from the pulley,
allowing it to spin freely once again.
The air gap between the front plate and the pulley is
adjusted by changing the number of shims located
on the compressor shaft under the front plate. (Refer
to the appropriate Service Manual for procedures to
measure and adjust air gap.)
Slide 55.02A-13a
Compressor Clutch
Pulley Bearing
Field CoilPulley
Pulley
Retaining
Snap Ring
Front Plate
Air Gap
Adjustment Shim
Retaining Nut

55.02A
Review the Service Manual procedures before
beginning this activity.
This compressor has been diagnosed with an
internal seal failure. The replacement compressor
does not come with a new compressor clutch.
Information for inspecting the compressor clutch is
found on what pages?
________________________________________
Follow the Service Manual procedure to remove
the compressor clutch.
Inspect the components for wear or damage and
record the results of your inspection below.
________________________________________
Reinstall the compressor clutch. What features of
the compressor and clutch are used to align the
clutch during installation?
________________________________________
________________________________________
________________________________________
New snap rings must be used to retain the clutch
coil to the compressor as well as pulley and bearing
to the compressor. (YES or NO)
In which direction must the snap ring beveled
surface face? (Inward or Outward)
To properly position the coil-to-compressor snap
ring, its eyelets must be positioned ____________
________________________________________
________________________________________
Check the clutch air gap and record your readings.
Measured: _______________________________
Standard Value: ___________________________
If the measured value differed from specification,
how is the air gap adjusted?
________________________________________
________________________________________
Activity
10S17E Swash
Plate Compressor
Clutch Removal and
Reinstallation
(Raider)

On what page of the Service Manual would you find
information for inspecting the compressor clutch?
________________________________________
________________________________________
Reinstall the clutch. What features of the
compressor and clutch are used to align the clutch
during installation?
________________________________________
________________________________________
Measured: _______________________________
Standard Value: ___________________________
________________________________________
________________________________________
Activity
VCR08 Rotary
Vane Compressor
Clutch Removal and
Reinstallation
(Mirage)

55.02A
Information for inspecting the compressor clutch is
found on what pages?
________________________________________
________________________________________
Reinstall the compressor clutch. What features of
the compressor and clutch are used to align the
clutch during installation?
________________________________________
________________________________________
Measured: _______________________________
Standard Value: ___________________________
________________________________________
________________________________________
Activity
QS90 Scroll
Compressor Clutch
Removal and
Reinstallation
(Lancer)

Refrigerant Temperature Switch
Most current Mitsubishi vehicles use a Refrigerant
Temperature Switch to disengage the compressor
clutch when system temperatures grow excessively
high.
Slide 55.02A-17a
Slide 55.02A-17b
ON → OFF: 278°F
OFF → ON: 248°F
It is wired in series with the compressor clutch and
opens when the temperature reaches 278º F and
closes below 248º F.

55.02A
A/C Pressure Sensor
Slide 55.02A-18a
The A/C Pressure Sensor connects to a Schrader
valve on the A/C liquid line and is sealed with a
rubber O-ring.
Signal
Processing
Ceramic
Diaphragm
Pressure
Port
Slide 55.02A-18b
The transducer detects pressure variances by
monitoring the deflection of a two piece ceramic
diaphragm. Pressures under the diaphragm are
converted to analog voltage signals within the
sensor and sent to the A/C controller.
• ECM disengages the clutch if high side pressure
rises above 460 psi and re-engages the clutch when
high side pressure drops below 290 psi.
• ECM disengages the clutch if high side pressure
drops below 28 psi and re-engages the clutch when
high side pressure rises above 34 psi.

The A/C-ECU (or Raider’s Front Control Module)
provides 5 volts to the transducer and monitors the
output voltage on the sensor circuit.
Since the A/C-ECU (or FCM) is part of the CAN
bus, high side pressure is continuously monitored
by the ECM.
Slide 55.02A-19a
A/C
CONTROL PANEL
A/C PRESSURE
SENSOR
INTERIOR
TEMPERATURE
SENSOR
NO
CONNECTION
VEHICLES WITH
AUTOMATIC
AIR CONDITIONING
SYSTEM
POWER
DISTRIBUTION
SYSTEM
AMBIENT AIR
TEMPERATURE
SENSOR
37
FUSIBLE
LINK
ETACS-ECU
ANALOG
INTERFACE
CIRCUIT
BLOWER
RELAY
POWER
TRANSISTOR
BLOWER
MOTOR
A/C-ECU
REFRIGERANT PRESSURE psi
OUTPUTVOLTAGE
0
1
2
3
5
4
145 290 435
Voltages representing normal system pressures
range between 0.451 volts and 4.519 volts.
Slide 55.02A-19b

55.02A
Slide 55.02A-20a
To prevent damage to system components,
compressors are equipped with a Pressure Relief
Valve to vent excessively high system pressures.
Pressure is vented at approximately 450 psi but
differs between compressors.
If a relief valve is ordered from Mitsubishi, two
valves may be included in the box (one gold & one
silver). This is due to thread differences between
compressors. Always use the appropriate color.
The FinTemperature Sensor (also called Evaporator
Temperature Sensor, Fin Thermo Sensor, or Air
Thermo Sensor) is a thermistor used to measure
the temperature of air flowing from the evaporator.
Some vehicles have the sensor inserted directly
into the evaporator fins (as shown above) while
others have it mounted on a bracket.
Slide 55.02A-20b
High Pressure Relief Valve
Fin Temperature Sensor
Sensor
TXV

Slide 55.02A-21b
TheA/C controller uses the sensor signal to optimize
system performance and to protect the evaporator
from freezing. As the evaporator temperature
increases, the sensor circuit resistance (and
voltage output to the controller) decreases. Normal
operating voltage ranges from 2.1 to 2.7V.
When the evaporator outlet air temperature drops
to 41º F the compressor clutch is disengaged.
RESISTANCE(kΩ)
TEMPERATURE ºF
8
6
4
2
0
14 32 50 68 86 104
Slide 55.02A-21a
Ambient Temperature Sensor
This thermistor is mounted at the front of the vehicle
typically under the bumper. The sensor signal is
hard wired to ETACS on GS and ZC platforms
(FCM on Raider) where it is made available to other
systems via CAN. With PS platform vehicles and
the i-MiEV, the signal is routed to the A/C-ECU.
Normal operating voltage ranges from 2.1 to 2.7V.

55.02A
AMBIENT AIR
TEMPERATURE
SENSOR
ETACS-ECU
ANALOG
INTERFACE
CIRCUIT
BLOWER
RELAY
POWER
TRANSISTOR
BLOWER
MOTOR
RELAY BOX
(PASSENGER
COMPARTMENT)
FUSIBLE LINK
GROUNDING
CONNECTOR
FUSIBLE
LINK 37
RHEOSTAT
A/C-
ECU
A/C
PRESSURE
SENSOR
JOINT
CONNECTOR (2)
AMBIENT
TEMPERATURE
SENSOR
NO
CONNECTION
REAR WINDOW DEFOGGER AND
DOOR MIRROR HEATER
Slide 55.02A-22a
Slide 55.02A-22b
PS Platform Vehicles
(Eclipse, Endeavor, Galant)
GS and ZC Platform Vehicles
(Lancer, Outlander,
Outlander Sport)

Used with automatic A/C systems, the sensor can
be located on either side of the dash (look for grill)
or directly on the A/C control panel. With some
older vehicles, the sensor was located on the
headliner. (A manual system may have the grill, but
no sensor.) The sensor is connected to a section of
flexible plastic hose as shown above.
Interior (Room) Temperature Sensor
Slide 55.02A-23b
Slide 55.02A-23a
An aspirator, typically located on the driver side of
the evaporator case, is connected to the opposite
end of the plastic hose leading from the sensor.
Hose from the
sensor connects
here.
This end of
the aspirator
is left open.
The aspirator is a venturi formed by a tapered tube
inside a plastic housing.
Slide 55.02A-23c
Aspirator

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