This document provides an introduction to car diagnostic (OBD) systems and summarizes some of their key functions and components. It discusses how early OBD systems would simply illuminate a malfunction light, while modern systems use standardized digital ports and diagnostic trouble codes to more precisely identify issues. It then briefly outlines several automotive systems and components that can be tested or monitored through OBD, including electric park brakes, tire pressure monitoring, crankshaft position sensors, smart keys, diesel particulate filters, and odometers. It concludes by defining some common automotive acronyms like SAS, SRS, and noting some references on the history of automotive technology.

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Car Diagnostic (OBD)
StudentName: Ahmed Naseh Latif
Class: 4 Stage – Group:B2
CourseTitle: Automotive Lab.
Department: Mechanic and MechatronicEngineering
College of Engineering
Salahaddin University-Erbil
Academic Year 2020-2021

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INTRODUCTION
On-board diagnostics (OBD) is an automotive term referring to a vehicle's self-
diagnostic and reporting capability. OBD systems give the vehicle owner or
repair technician access to the status of the various vehicle sub-systems. The
amount of diagnostic information available via OBD has varied widely since its
introduction in the early 1980s versions of on-board vehicle computers. Early
versions of OBD would simply illuminate a malfunction indicator light or "idiot
light" if a problem was detected but would not provide any information as to the
nature of the problem. Modern OBD implementations use a standardized digital
communications port to provide real-time data in addition to a standardized
series of diagnostic trouble codes, or DTCs, which allow a personto rapidly
identify and remedy malfunctions within the vehicle.
Special Function Tests:
 Electric Park Brake (EPB) is a caliper with an additional motor
(motor on caliper) that operates the parking brake. The EPB system
is electronically controlled and consists of the EPB switch, the EPB
caliper and the electronic control unit (ECU).
 The purposeof the tire pressure monitoring system (TPMS)in your
vehicle is to warn you that at least one or more tires are
significantly under-inflated, possibly creating unsafe driving
conditions. The TPMS low tire pressureindicator is a yellow
symbol that illuminates on the dashboard instrument panel in the
shape of a tire cross-section(that resembles a horseshoe) with an
exclamation point.
 Drivability technicians have experienced learn and relearn
procedures for years. The Crankshaft Position Variation Learn
Procedure — concerning the relationship of the Crankshaft Position
sensor or CKP to the crankshaft reluctor — was introduced in 1997
and has been used more broadly since 1998.
 The meaning of SAS is Side-Impact Protection and other
meanings are located at the bottom which take place within Car
terminology and SAS has 1 different meaning. All meanings which
belong to SAS abbreviation are take part only within Car
terminology and other meanings are not found.

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 A smart key is an electronic access and authorization system that is
available either as standard equipment, or as an option in several car
designs. It was first developed by Siemens in 1995 and introduced
by Mercedes-Benz under the name "Keyless-Go" in 1998 on the
W220 S-Class, after the design patent was filed by Daimler-Benz
on May 17, 1997.
 A diesel particulate filter (DPF) is a device designed to
remove diesel particulate matter or soot from the exhaust gas of
a diesel engine.
 is the process of clearing all the long term memory from
the ECU's memory. These variables trim idle speed, fuel, spark, and
more. The ECU will also store trouble codes for diagnostic
capability.
 An odometer or odograph is an instrument used for measuring
the distance traveled by a vehicle, such as a bicycle or car. The
device may be electronic, mechanical, or a combination of the two
(electromechanical).
 Vehicle Adaptations are devices that are fitted to your vehicle,
providing you with a mobility solution for travel. Our adaptations
have been designed to improve the quality of your car journeys,
whether you are the driver or passenger.
 SRS stands for supplemental restraint system, which relates to
your vehicle's airbags.

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REFERENCES
 "PersonalNotes of the Automobile Trade". The Horseless
Age. 40 (4): 58. 1917-05-17. hdl:2027/njp.32101048981896.
 Robert Asher (2003). "Connecticut Inventors". Connecticut
Humanities Council.
 "Benjamin Franklin and His Inventions". learn.fi.edu.
Archived from the original on 2015-08-29.Retrieved 2019-
10-10.