The document provides a comprehensive list of Ford OBD1 diagnostic trouble codes, detailing 2-digit and 3-digit codes along with their definitions. Each code indicates specific issues within the vehicle's engine management system, such as sensor failures, circuit issues, and system malfunctions. This information is useful for troubleshooting and identifying problems in Ford vehicles equipped with OBD1 systems.

1. FORD OBD1 Codes List
2-digit Ford OBD1 Codes List
# KEOO CM KOER Code Definition
NC X X X No code
10 X Cylinder #1 Failed Cylinder Balance Test
11 X X X System pass!
12 X Cannot control RPM during ER Self-Test high RPM check.
13 X Cannot control RPM during ER Self-Test low RPM check.
14 X
Two or more successive erratic Profile Ignition Pickup (PIP) pulses occurred, resulting in a
possible engine miss or stall.
15 X EEC permanent Read Only Memory (ROM) test failed.
15 X EEC battery powered Keep Alive Memory (KAM) test failed.
16 X IDM signal not received.
16 X RPM too low to perform HEGO test.
17 X RPM below Self-Test limit with Idle Air Control off
18 X SPOUT circuit open or spark angle word failure.
18 X IDM circuit failure or SPOUT circuit grounded
19 X Failure in EEC internal voltage.
19 X Cylinder Identification CID circuit failure.
19 X RPM erratic, dropped too low during test.
20 X Cylinder #2 Failed Cylinder Balance Test.
21 X X X ECT out of self test range 0.3 to 3.7 volts.
22 X X X MAP/BP sensor out of self test range
23 X X Closed throttle TPS voltage higher or lower than expected
24 X X X ACT sensor out of self test range 0.3 to 3.7 volts.
25 X Knock not sensed during dynamic test
26 X MAF sensor was greater than 0.7 volts with engine off
26 X MAF sensor was not between 0.2 and 1.5 volts with engine running.
26 X X TOT sensor out of self test range.
27 ?
28 X X VAT sensor out of self test range.
28 X Loss of IDM, right side.
29 X Insufficient input from vehicle speed sensor

2. 30 X Cylinder #3 Failed Cylinder Balance Test.
31 X X PFE or EVP circuit below minimum voltage of 0.24 volts
31 X PFE or EVP circuit has intermittently failed below minimum voltage of 0.24 volts.
32 X X EVP circuit below minimum voltage of 0.24 volts.
32 X EVP circuit has intermittently failed below minimum voltage of 0.24 volts.
33 X X EGR valve opening not detected
34 X X PFE or EVP circuit above the closed limit of 0.67 volts
34 X PFE or EVP circuit has intermittently failed above the closed limit of 0.67 volts.
35 X X PFE or EVP circuit above the maximum limit of 4.81 volts.
35 X PFE or EVP circuit has intermittently failed above the maximum limit of 4.81 volts
39 X AXOD converter bypass clutch not applying properly
40 X Cylinder #4 Failed Cylinder Balance Test.
41 X HEGO sensor circuit indicates system lean (right side).
41 X No HEGO switching detected always lean (right side).
42 X HEGO sensor circuit indicates system rich (right side).
42 X No HEGO switching detected always rich (right side).
43 X HEGO lean at Full Throttle.
44 X X Thermactor Air Injection system inoperative (Right side).
45 X DIS coil pack 3 circuit failure or coil 1 primary circuit failure.
45 X Thermactor secondary air is misdirected
46 X DIS coil pack 1 circuit failure or coil 2 primary circuit failure.
46 X Thermactor air not bypassed during self test.
47 X 4WD switch closed.
47 X Measured air flow too low at base idle
48 X Loss of IDM, left side.
48 X Measured air flow too high at base idle
49 X SPOUT signal default to 10 BTDC.
49 X 1 - 2 shift error (E4OD).
50 X Cylinder #5 Failed Cylinder Balance Test.
51 X X ECT sensor signal is greater than the Self-Test maximum of 4.6 volts.
52 X X X Power steering pressure switch always open or closed.
53 X TPS circuit above maximum 4.5 volts.
53 X TPS circuit has intermittently failed above maximum 4.5 volts.
54 X X ACT sensor signal is greater than the Self-Test maximum of 4.6 volts.

3. 55 X Keyed power input to processor is open.
56 X X MAF circuit above maximum voltage of 4.5volts.
56 X X TOT sensor output is greater than Self-Test maximum value of 4.8 volts.
57 X Octane adjust service pin in use / circuit grounded.
57 X AXOD Neutral pressure switch circuit failed open.
58 X X VAT indicated -40F / circuit open.
59 X X Low speed fuel pump circuit failure.
59 X X 2 - 3 shift error (E4OD).
60 X Cylinder #6 Failed Cylinder Balance Test.
61 X ECT sensor is less than the Self-Test minimum of 0.2 volts
61 X ECT sensor has intermittently failed below 0.2 volts
62 X 4/3 or 3/2 pressure switch circuit failed open
62 X Converter clutch error (E4OD).
63 X TPS circuit below minimum 0.6 volts
63 X TPS circuit has intermittently failed below minimum 0.6 volts.
64 X ACT sensor is less than the Self-Test minimum of 0.2 volts.
64 X ACT sensor has intermittently failed below 0.2 volts.
65 X Overdrive OFF switch was not cycled during KOER test (user error).
66 X MAF sensor went below 0.4 volts during the last 80 warm-up cycles.
66 X X TOT sensor output was less than Self-Test minimum value of 0.15 volts.
67 X X Neutral safety circuit failure
67 X A/C circuit was on during KOER Self-Test
68 X Transmission recently overheated, or TOT sensor intermittently failed below 0.2 volts.
69 X 3 - 4 shift error.
70 X Cylinder #7 Failed Cylinder Balance Test.
71 X Software re-initialization detected or Cluster ControlAssembly circuit failed
72 X Power interruption detected or Message Center Control Assembly circuit failed.
72 X Insufficient MAF/MAP change during Dynamic Response Test (user error).
73 X TPS senor did not exceed 25% rotation during Dynamic Response Test (user error)
74 X Brake On/Off switch not actuated during KOER test (user error).
75 X Brake On/Off switch failure always ON.
76 X Insufficient VAT change during Dynamic Response Test (user error)
77 X System failed to recognize brief WOT during Dynamic Response Test (user error)
79 X A/C or defrost on during self test.

4. 80 X Cylinder #8 Failed Cylinder Balance Test
81 X Air management 2 circuit failure (AM2/TAD).
81 X MAP sensor vacuum was not greater than 2 in-Hg (7 kPa) during normal vehicle operation
82 X Air management 1 circuit failure (AM1/TAB) .
83 X EGR Control solenoid circuit failure.
83 X High speed electro-drive fan circuit failure.
83 X X Low speed fuel pump relay circuit open
84 X X EGR Vacuum Solenoid circuit failure.
85 X X Canister Purge Solenoid circuit failure.
86 X 3 4 Shift solenoid circuit failure.
86 X Adaptive fuel limit reached.
87 X
Fuel pump primary circuit failure. When the FP relay was activated by the EEC, voltage was not
detected on the control circuit.
87 X Voltage was not detected on Fuel Pump Monitor while the engine was running.
88 X Electro-drive fan circuit failure.
88 X Loss of dual plug input control
89 X Converter clutch solenoid circuit failure.
90 X All cylinders passed Cylinder Balance Test.
91 X Shift solenoid 1 circuit failure (E4OD).
91 X No HEGO switching detected always lean (left side).
91 X HEGO sensor circuit indicates system lean (left side).
92 X Shift solenoid 2 circuit failure (E4OD).
92 X No HEGO switching detected always rich (left side).
92 X HEGO sensor circuit indicates system rich (left side).
93 X Coast clutch solenoid circuit failure (E4OD).
94 X Converter clutch solenoid circuit failure (E4OD).
94 X Thermactor Air Injection system inoperative (left side).
95 X X
Fuel pump secondary circuit failure. The EEC senses infinite resistance to ground from the fuel
pump on the Fuel Pump Monitor circuit.
96 X X
Fuel pump secondary circuit failure. The EEC did not sense battery voltage on the Fuel Pump
Monitor circuit.
97 X Overdrive cancel indicator light circuit failure (E4OD)
98 X X Electronic pressure control driver open in EEC (E4OD).
98 X Hard fault present
99 X X Electronic pressure control circuit failure (E4OD).

5. 99 X EEC system hasnt learned to control idle.
3-digit Ford OBD1 Codes List
# KOEO CM KOER 3-Digit Code Definitions
NC X X X No Codes
111 X X X System pass
112 X
ACT sensor signal is less than the Self-Test minimum of
0.2 volts
112 X
ACT circuit has intermittently failed below minimum 0.2
volts.
113 X
ACT sensor signal is greater than the Self-Test
maximum of 4.6 volts.
113 X
ACT circuit has intermittently failed above the
maximum of 4.6 volts
114 X X ACT out of self test range 0.3 to 3.7 volts.
116 X X ECT out of self test range 0.3 to 3.7 volts.
117 X
ECT sensor signal is less than the Self-Test minimum of
0.2 volts.
117 X
ECT circuit has intermittently failed below minimum 0.2
volts.
118 X
ECT sensor signal is greater than the Self-Test maximum
of 4.6 volts.
118 X
ECT circuit has intermittently failed above the maximum
of 4.6 volts
121 X X
Closed throttle TPS voltage higher or lower than
expected.
121 X
TP sensor was inconsistent with the MAF/MAP value in
the last 80 drive cycles.
122 X TPS circuit below minimum 0.6 volts.
122 X
TPS circuit has intermittently failed below minimum 0.6
volts.
123 X TP circuit above maximum 4.5 volts.
123 X
TPS circuit has intermittently failed above maximum 4.5
volts.
124 X
TP sensor was higher than expected with the MAF/MAP
value in the last 80 drive cycles.

6. 125 X
TP sensor was lower than expected with the MAF/MAP
value in the last 80 drive cycles
126 X X X MAP/BP sensor out of self test range 1.4 to 1.6 volts.
128 X
MAP sensor vacuum was not greater than 2 in-Hg (7
kPa) during normal vehicle operation.
129 X
Insufficient MAF/MAP change during Dynamic
Response Test.
136 X HEGO sensor circuit indicates system lean (left side)
137 X HEGO sensor circuit indicates system rich (left side)
139 X No HEGO sensor switching detected or disconnected (left side)
141 X HEGO sensor circuit indicates system lean (both sides)
144 X
No HEGO sensor switching detected or disconnected
(right side)
157 X
MAF sensor went below 0.4 volts during the last 80
warm-up cycles.
158 X X
MAF sensor went above 4.5 volts during the last 80
warm-up cycles.
159 X MAF signal was greater than 0.70 volt during KOEO.
159 X
MAF signal was not between 0.20 and 1.50 volts during
KOER.
167 X
TPS did not exceed 25% rotation during the Dynamic
Response Test.
171 X
Fuel system at adaptive limit, HEGO unable to switch
(right side)
172 X HEGO sensor circuit indicates system lean (right side)
173 X HEGO sensor circuit indicates system rich (right side)
174 X HEGO switching time is slow
175 X
Fuel system at adaptive limit, HEGO unable to switch
(left side)
176 X HEGO sensor circuit indicates system lean (left side)
177 X HEGO sensor circuit indicates system rich (left side)
178 X HEGO switching time is slow
179 X
Right side still rich, at leanest adaptive limit, during part
throttle.
181 X
Right side still lean, at richest adaptive limit, during part
throttle.
182 X Right side still rich, at leanest adaptive limit, at idle.

7. 183 X Right side still lean, at richest adaptive limit, at idle.
184 X MAF higher than expected
185 X MAF lower than expected
186 X Injector pulse width longer than expected
187 X Injector pulse width shorter than expected
188 X
Left side still rich, at leanest adaptive limit, during part
throttle.
189 X
Left side still lean, at richest adaptive limit, during part
throttle
191 X Left side still rich, at leanest adaptive limit, at idle.
192 X Left side still lean, at richest adaptive limit, at idle.
193 X Flexible Fuel sensor circuit failure
194 X Run cylinder balance diagnostic test.
195 X Run cylinder balance diagnostic test.
211 X
Two or more successive erratic Profile Ignition Pickup
(PIP) pulses occurred, resulting in a possible engine miss
or stall.
212 X Loss of IDM input to EEC or SPOUT circuit grounded.
213 X SPOUT circuit open
214 X Cylinder Identification (CID) circuit failure
215 X EEC detected coil 1 primary circuit failure
216 X EEC detected coil 2 primary circuit failure
217 X EEC detected coil 3 primary circuit failure
218 X Loss of IDM signal (left side)
219 X
SPOUT failure, spark timing has defaulted to 10 degrees
BTDC.
222 X Loss of IDM signal (right side)
223 X Loss of Dual Plug Inhibit control
224 X Erratic IDM input to processor
225 X
Knock Sensor (KS) signal not sensed during dynamic
response test.
226 X IDM signal not received
244 X Camshaft Position (CMP) Sensor failure.
311 X Thermactor air system inoperative (right side)
312 X Thermactor air misdirected upstream during self test

8. 313 X
Thermactor air not bypassed during self test.
314 X Thermactor air system inoperative (left side)
326 X X
PFE or DPFE circuit voltage lower than expected with
zero EVR duty cycle
327 X X X
DPFE or EVP circuit below minimum voltage of 0.2
volts.
328 X X X EVP circuit below minimum voltage of 0.24 volts.
332 X X EGR valve opening not detected.
334 X X X
DPFE or EVP circuit above the closed limit of 0.67
volts.
335 X PFE or DPFE sensor voltage out of Self-Test range.
336 X X
EVP or DPFE circuit voltage above maximum voltage
with zero EVR duty cycle.
337 X X X
DPFE or EVP circuit above the maximum limit of 4.81
volts.
338 X ECT lower than expected.
339 X ECT higher than expected.
341 X
Octane Adjust shorting bar is not in or the OCT ADJ
circuit is open.
381 X
Frequent A/C compressor clutch (ACCS) cycling less
than 8.5 seconds.
411 X Cannot control rpm during KOER low RPM check
412 X Cannot control rpm during KOER high RPM check
452 X
Computer detected an error in the VSS or PSOM signal
during the last 80 warm-up cycles
461 X Engine over speed was detected
511 X X X EEC permanent Read Only Memory (ROM) test failed.
512 X
EEC battery powered Keep Alive Memory (KAM) test
failed
513 X Failure in EEC processor internal voltage.
519 X Power steering pressure switch circuit open.
521 X
Power steering pressure switch did not change state
during KOER test
522 X Vehicle not in PARK or NEUTRAL during KOEO

9. 524 X X
When the PCM commanded the fuel pump on, voltage
was not detected on FPM.
525 X X Vehicle in gear or A/C on during Self-Test
526 X Neutral Pressure Switch closed or A/C on
527 X Neutral Drive Switch open or A/C on
528 X Clutch Switch Circuit failure
529 X
Data Communications Link or Electronic Instrument
Cluster circuit failure.
532 X
Data Communications Link or Electronic Instrument
Cluster circuit failure.
533 X
Data Communications Link or Electronic Instrument
Cluster circuit failure.
536 X X
Brake On/Off circuit failure / switch not actuated during
KOER test
538 X
Insufficient RPM change during KOER dynamic
response test/ Operator error
539 X A/C or Defroster ON during KOEO test
542 X X Fuel pump circuit failure
543 X X
When the PCM commanded the fuel pump on, voltage
was not detected on FPM.
551 X Intake Manifold Runner Control (IMRC) circuit failure
552 X Air management 1 circuit failure (AM1/TAB)
553 X Air management 2 circuit failure (AM1/TAD)
554 X
Fuel Pressure Regulator Control (FPRC) solenoid circuit
failure
556 X X Fuel Pump circuit failure
557 X X Fuel pump relay coil resistance failure
558 X EGR Vacuum Regulator circuit failure
559 X Air Conditioning On relay circuit failure
563 X High Speed Electro-Drive Fan circuit failure
564 X Electro-Drive Fan circuit failure
565 X Canister purge circuit failure
566 X 3 4 Shift Solenoid failure
569 X Canister purge 2 circuit failure
571 X EGR Atmospheric Regulator circuit failure.
572 X EGR Vacuum Regulator circuit failure.

10. 578 X
A/C Pressure (ACP) sensor VREF circuit is short to
ground.
579 X
A/C Pressure (ACP) sensor circuit is above maximum
voltage.
581 X
When the cooling fan was activated, the circuit exceeded
current draw.
582 X
Open or short to power in the power-to-cooling fan
circuit.
583 X
When the fuel pump was activated, the power-to-pump
circuit exceeded the normal current draw
584 X Variable Control Relay Module circuit grounded.
585 X A/C clutch circuit exceeded the normal current draw
586 X A/C clutch circuit open or shorted to power
587 X X Data Communications Link (DCL) error
593 X X Oxygen Sensor Heater circuit failure
617 X 1 - 2 shift error (E4OD)
618 X 2 - 3 shift error (E4OD)
619 X 3 - 4 shift error (E4OD)
621 X Shift solenoid #1 circuit failure
622 X Shift solenoid #2 circuit failure
623 X
Overdrive light circuit failure
624 X X
Electronic Pressure Control solenoid or driver circuit
failure
625 X X Electronic Pressure Control driver open in EEC
626 X Coast clutch solenoid circuit failure (E4OD)
627 X Converter clutch solenoid circuit failure (E4OD)
628 X Converter clutch Lock-Up error (E4OD)
629 X X Converter clutch control circuit failure
631 X Overdrive light circuit failure
632 X Overdrive cancel switch not changing state (E4OD)
633 X 4WD switch is closed
634 X X
Transmission Manual Lever Position Sensor circuit out
of self test.
636 X X TOT sensor voltage out of self test range.

11. 637 X X TOT sensor circuit above maximum voltage
638 X X TOT sensor circuit below minimum voltage
639 X X Insufficient input from the Transmission Speed Sensor
641 X Shift solenoid #3 circuit failure
643 X X Converter Clutch Control circuit failure
645 X Incorrect gear ratio obtained for first gear
646 X Incorrect gear ratio obtained for second gear
647 X Incorrect gear ratio obtained for third gear
648 X Incorrect gear ratio obtained for fourth gear
649 X Electronic Pressure Control range failure
651 X Electronic Pressure Control circuit failure
652 X Modulated Converter Clutch Control solenoid output circuit error
653 X
Transmission Control Switch was not cycled during
KOER Self-Test.
654 X MLP sensor not in park position
656 X Converter Clutch Control continuous slip error detected
657 X Transmission over temperature condition occurred.
659 X
High vehicle speed detected while the vehicle was in
PARK.
667 X
Transmission Manual Lever Position Sensor circuit
shorted
668 X Transmission Manual Lever Position Sensor circuit open
675 X MLP circuit voltage was out of the expected range
691 X 4WD switch circuit failure.
998 Hard fault present
NC X X X No Codes