Ford OBD-I Codes
1981-1995 Ford, Lincoln and Mercury EEC-IV. 278 codes. Two- and three-digit self-test codes. Jumper the self-test input, key on, count the flashes.
Popular Ford codes
- 11: System pass, no fault found during self test
- 14: Profile ignition pickup circuit failure
- 21: Engine coolant temperature sensor out of self test range
- 33: EGR valve not closing properly or EGR valve opening not detected
- 41: Fuel system indicates lean or oxygen sensor not switching
- 51: Engine coolant temperature circuit open
- 63: Throttle position sensor circuit below minimum voltage
- 87: Primary fuel pump circuit failure
Ford (278)
Jump to a system
Powertrain - Computer and Auxiliary Controls
- 11System pass, no fault found during self test
- 12Engine RPM above the self test upper limit during the running test
- 13Engine RPM below the self test lower limit or idle speed motor did not move
- 15Readout memory or keep alive memory test failed
- 17Engine RPM below the self test limit with idle speed control off
- 19PCM internal voltage fault or cylinder identification sensor input failure
- 38Idle speed control or idle tracking throttle position sensor open circuit
- 55Key power check during self test
- 58Idle tracking switch circuit open or grounded
- 68Idle tracking switch closed or transmission fluid over temperature
- 71Idle tracking switch closed on pre-position or software reinitialization detected
- 78Reinitialization check during self test
- 83Integrated relay control module fault or electric drive fan circuit failure
- 111System pass
- 411Cannot control RPM during KOER low RPM check
- 412Cannot control RPM during KOER high RPM check
- 415Idle air control solenoid circuit failure
- 416Idle air control solenoid circuit failure
- 511Read out memory test failure KOEO
- 512Keep alive memory test failure
- 513PCM internal voltage failure (KOEO)
- 522Vehicle not in park or neutral during the KOEO test
- 526Neutral position switch circuit closed, A/C on
- 527Neutral drive switch circuit open, A/C on
- 528Clutch position switch circuit failure
- 562Engine coolant blower motor relay circuit malfunction
- 563High speed electric fan circuit failure
- 564Electric fan circuit failure
- 581Power to fan circuit over current
- 582Fan circuit open
- 633Four wheel drive switch closed during the KOEO test
Powertrain - Ignition
- 14Profile ignition pickup circuit failure
- 16Ignition diagnostic module circuit fault or engine RPM out of range for the test
- 18Spark output circuit open or ignition diagnostic signal fault
- 25Knock not sensed during the dynamic response test
- 28Loss of ignition diagnostic module signal on the right bank
- 48Loss of ignition diagnostic module signal on the left bank or distributorless ignition coil pack fault
- 49Spark output signal default to 10 degrees or 1-2 shift error
- 88Loss of dual plug input control or electric drive fan circuit failure
- 211Profile ignition pickup circuit failure
- 212Loss of ignition diagnostic module input to PCM or SPOUT circuit grounded
- 213Spark output (SPOUT) circuit open
- 214Cylinder identification circuit failure
- 215PCM detected coil 1 primary circuit failure (EI)
- 216PCM detected coil 2 primary circuit failure (EI)
- 217PCM detected coil 3 primary circuit failure (EI)
- 218Loss of ignition diagnostic module signal LH side (dual plug EI)
- 219Spark timing error
- 221Spark timing error
- 222Loss of ignition diagnostic module signal RH side (dual plug EI)
- 223Loss of dual plug ignition control (dual plug EI)
- 224PCM detected a primary circuit failure on ignition coils 1, 2, 3 or 4 (EI)
- 225Knock not sensed during dynamic response test KOER
- 226Ignition diagnostic module signal not received (EI)
- 232PCM detected coil 1, 2, 3 or 4 primary circuit failure (EI)
- 238PCM detected coil 4 primary circuit failure
- 241Ignition control module diagnostic monitor signal malfunction
- 244Cylinder identification sensor circuit failure (2.0L)
- 341Octane adjust service pin open
Powertrain - Fuel/Air Metering
- 21Engine coolant temperature sensor out of self test range
- 22Manifold absolute pressure or barometric pressure sensor out of self test range
- 23Throttle position sensor out of self test range
- 24Intake air temperature or air charge temperature sensor out of self test range
- 26Mass air flow or vane air flow sensor out of self test range
- 36Fuel system indicates lean at idle
- 37Fuel system indicates rich at idle
- 41Fuel system indicates lean or oxygen sensor not switching
- 42Fuel system indicates rich or oxygen sensor not switching
- 43Oxygen sensor indicates lean at wide open throttle or throttle position sensor below idle
- 51Engine coolant temperature circuit open
- 53Throttle position sensor circuit above maximum voltage
- 54Intake air temperature or air charge temperature circuit open
- 56Transmission fluid temperature circuit open or mass air flow sensor above maximum voltage
- 61Engine coolant temperature circuit grounded
- 63Throttle position sensor circuit below minimum voltage
- 64Intake air temperature or air charge temperature circuit grounded
- 66Mass air flow or vane air flow sensor below minimum voltage or transmission fluid temperature circuit grounded
- 72Insufficient manifold pressure or air flow change during the dynamic response test
- 73Insufficient throttle position change during the dynamic response test
- 76Insufficient vane air flow sensor output change during the dynamic response test
- 85Adaptive fuel lean limit reached or canister purge circuit failure
- 87Primary fuel pump circuit failure
- 95Fuel pump circuit open between PCM and motor ground
- 96Fuel pump circuit open between battery and PCM or high speed fuel pump relay fault
- 112Intake air temperature or air charge temperature sensor circuit below minimum voltage
- 113Intake air temperature or air charge temperature sensor circuit above maximum voltage
- 114Intake air temperature or air charge temperature higher or lower than expected
- 116Engine coolant temperature higher or lower than expected
- 117ECT sensor circuit below minimum voltage
- 118ECT sensor circuit above maximum voltage
- 121Closed throttle voltage out of range or throttle position voltage inconsistent with the mass air flow sensor
- 122Throttle position sensor circuit below minimum voltage
- 123Throttle position sensor circuit above maximum voltage
- 124Throttle position sensor voltage higher than expected
- 125Throttle position sensor voltage lower than expected
- 126Manifold absolute pressure or barometric pressure sensor higher or lower than expected
- 128Manifold absolute pressure sensor vacuum hose damaged or disconnected
- 129Insufficient manifold absolute pressure or mass air flow change during dynamic response test KOER
- 136System indicates lean (bank no. 1)
- 137System indicates rich (bank no. 2)
- 138Cold start injector flow insufficient
- 139No HO2S switch detected
- 141Flexible fuel control system fault
- 144No HO2S switch detected
- 157Mass air flow sensor circuit below minimum voltage
- 158Mass air flow sensor circuit above maximum voltage
- 159Mass air flow sensor higher or lower than expected
- 167Insufficient throttle position change during dynamic response test
- 171Fuel system at adaptive limits
- 172HO2S system indicates lean
- 173HO2S system indicates rich
- 174HO2S switching time is slow
- 175Fuel system at adaptive limits (bank no. 2)
- 176System indicates lean (bank no. 2)
- 177System indicates rich (bank no. 2)
- 178HO2S switch time is slow (bank no. 1)
- 179Fuel system at the lean adaptive limit at part throttle with the system rich on 1.9L, 2.0L, 2.3L HSC, 2.5L and 3.0L engines
- 181Fuel system at the rich adaptive limit at part throttle with the system lean on 1.9L, 2.0L, 2.3L HSC, 2.5L and 3.0L engines
- 182Fuel system at the lean adaptive limit at idle with the system rich on 1.9L, 2.3L, 2.5L, 3.0L, 3.8L SC, 4.6L, 7.0L and 7.5L engines
- 183Fuel system at the rich adaptive limit at idle with the system lean on 1.9L, 2.3L, 3.0L, 3.8L SC, 4.6L, 7.0L and 7.5L engines
- 184Mass air flow sensor circuit voltage higher than expected
- 185Mass air flow sensor circuit voltage lower than expected
- 186Injector pulse width higher than expected (with BARO sensor)
- 187Injector pulse width lower than expected (with BARO sensor)
- 188Fuel system at lean adaptive limit
- 189Fuel system at rich adaptive limit
- 191Fuel system at lean adaptive limit (front)
- 192Fuel system at rich adaptive limit (front)
- 193Flexible fuel sensor circuit failure
- 338Engine coolant temperature lower than expected
- 339Engine coolant temperature higher than expected
- 524Low speed fuel pump circuit open
- 542Fuel pump circuit open between the PCM and the motor ground
- 543Fuel pump circuit open between the battery and the PCM
- 554Fuel pump relay control circuit failure
- 556Fuel pump relay primary circuit failure
- 557Low speed fuel pump primary circuit failure
- 583Power to fuel pump over current
- 593Heated oxygen sensor heater circuit malfunction
Powertrain - Other
- 27Vehicle speed sensor signal fault on 2.3L turbo models
- 29Insufficient input from the speedometer module or vehicle speed sensor
- 47Four wheel drive switch closed during self test or measured air flow low at base idle
- 52Power steering pressure switch circuit open or no state change
- 77Operator error during the dynamic response test
- 98Hard fault present during self test
- 194Cylinder balance test malfunction
- 195Cylinder balance test malfunction
- 452Insufficient input from vehicle speed sensor to PCM
- 519Power steering pressure switch circuit open KOEO
- 521Power steering pressure switch circuit did not change states KOER
- 525Vehicle in gear with A/C on
- 538Insufficient RPM change during KOER dynamic response test or Invalid cylinder balance test due to throttle movement during test or Invalid cylinder balance test due to cylinder identification sensor circuit failure
- 584Power ground circuit open
- 625Hard fault present or electronic pressure control driver open in the PCM
- 691Four wheel drive selector fault with incorrect engine speed or vehicle speed
- 998Hard fault present
Powertrain - Auxiliary Emissions Controls
- 31EGR valve position or pressure feedback circuit below minimum voltage
- 32EGR valve not controlling or not seated
- 33EGR valve not closing properly or EGR valve opening not detected
- 34EGR valve opening not detected or EGR pressure transducer fault
- 35EGR valve position or pressure feedback circuit above maximum voltage
- 44Secondary air system inoperative
- 45Secondary air upstream during self test
- 46Secondary air not bypassed during self test or ignition coil primary circuit fault
- 81Secondary air diverter circuit failure
- 82Secondary air bypass circuit failure
- 84EGR valve position or EGR control circuit failure
- 311Secondary air system inoperative, including during the KOER test on bank 1 with dual oxygen sensors
- 312AIR misdirected during KOER
- 313AIR not bypassed during KOER
- 314AIR system inoperative during KOER
- 326EGR temperature sensor circuit above maximum voltage (2.0L, 2.3L HSC and 3.0L SHO)
- 327EGR circuit below minimum voltage
- 328EGR valve position sensor closed valve voltage lower than expected
- 332Insufficient EGR flow detected
- 334EGR valve position sensor closed valve voltage higher than expected
- 335Pressure feedback EGR sensor voltage higher or lower than expected during KOEO
- 336Pressure feedback EGR circuit voltage higher than expected
- 337EGR valve position or pressure feedback EGR circuit above maximum voltage
- 551Intake air control circuit failure KOEO
- 552Secondary air bypass circuit failure during the KOEO test
- 553Secondary air bypass circuit failure during the KOEO test
- 558EGR vacuum regulator circuit failure
- 565Canister purge circuit failure KOEO
- 569Auxiliary canister purge circuit failure
- 571EGR circuit failure
- 572EGR circuit failure
Powertrain - Transmission
- 39AXOD converter bypass clutch not applying properly
- 57Transaxle neutral position switch circuit failed open
- 59AXOD neutral position switch failed open or 2-3 shift error
- 62Torque converter clutch error or AXOD pressure switch fault
- 65Overdrive cancel or transmission control switch circuit did not change states
- 67Park neutral or clutch switch circuit fault or A/C input high
- 693-4 shift error or AXOD pressure switch fault
- 70EEC IV data transaxle circuit failed
- 86Shift solenoid circuit failure or adaptive fuel rich limit reached
- 89Converter clutch override circuit failure or exhaust heat control fault
- 91Shift solenoid 1 circuit failure or oxygen sensor indicates lean
- 92Shift solenoid 2 circuit failure or oxygen sensor indicates rich
- 93Throttle position sensor input low or converter clutch solenoid circuit failure
- 94Torque converter clutch solenoid circuit failure or secondary air injection inoperative
- 97Transmission control indicator lamp circuit failure
- 99Electronic pressure control circuit failure or idle not learned
- 490Gear shift 1-2 malfunction
- 566Shift solenoid circuit failure KOEO
- 590Gear shift 2-3 malfunction
- 6171-2 shift error
- 6182-3 shift error
- 6193-4 shift error
- 620Torque converter clutch excessive clutch slip
- 621Shift solenoid 1 circuit failure KOEO
- 622Shift solenoid 2 circuit failure KOEO
- 623Transmission control indicator lamp circuit failure
- 624Electronic pressure control circuit failure
- 626Converter clutch solenoid circuit failure KOEO
- 627Torque converter clutch solenoid circuit failure
- 628Excessive torque converter clutch slippage
- 629Torque converter clutch solenoid circuit failure
- 631Transmission control indicator lamp circuit failure KOEO
- 632Torque converter solenoid circuit did not change states during KOER
- 634Manual lever position sensor voltage higher or lower than expected
- 636Transmission fluid temperature higher or lower than expected
- 637Transmission fluid temperature sensor circuit above maximum voltage
- 638Transmission fluid temperature sensor circuit below minimum voltage
- 639Insufficient input from turbine speed sensor
- 641Shift solenoid 3 circuit failure
- 643Torque converter clutch circuit failure
- 645Improper gear ratio in 1st gear
- 646Improper gear ratio in 2nd gear
- 647Improper gear ratio in 3rd gear
- 648Improper gear ratio in 4th gear
- 649Electronic pressure control higher or lower than expected
- 650Overdrive selection switch no signal change during the KOEO test
- 651Electronic pressure control circuit failure
- 652Torque converter clutch solenoid circuit failure
- 653Torque converter solenoid did not change states during KOER
- 654Manual lever position sensor indicating not in park during self test
- 655Manual lever position sensor indicating not in neutral during self test
- 656Torque converter clutch slippage error
- 657Transmission over temperature condition
- 659High vehicle speed in park indicated
- 662Shift solenoid 2 circuit failure
- 667Transmission range sensor circuit below minimum voltage
- 668Transmission range sensor circuit above maximum voltage
- 670Transmission range sensor voltage high or low
- 675Transmission range sensor circuit voltage out of range
- 680Automatic transmission fluid temperature high
- 690Gear shift 3-4 malfunction
- 920Shift solenoid 2 circuit malfunction during the KOEO test
- 930Transmission coast clutch solenoid circuit malfunction during the KOEO test
- 940Torque converter clutch solenoid circuit malfunction during the KOEO test
- 980PCM transmission fluid pressure control open driver circuit during the KOEO test
- 990Transmission fluid pressure solenoid circuit malfunction during the KOEO test
Chassis
- 74Brake on/off circuit open during self test
- 75Brake on/off circuit closed or ECA input open
- 536Brake pedal switch circuit failure or not actuated during the KOER test
Body
- 79A/C or defrost on during self test
- 381Erratic A/C compressor clutch cycling
- 453Cruise control servo leaking down during the KOER test
- 454Cruise control servo leaking up during the KOER test
- 455Insufficient engine speed increase during the cruise control KOER test
- 456Insufficient engine speed decrease during the cruise control KOER test
- 457Cruise control master or selector switch circuit malfunction during the KOEO test
- 458Cruise control master or selector switch short to ground during the KOEO test
- 459Cruise control system ground open circuit during the KOEO test
- 532Instrument panel circuit malfunction
- 539A/C on or defrost on during KOEO
- 559A/C on relay circuit failure
- 567Cruise control vent valve circuit malfunction
- 568Cruise control vacuum valve circuit malfunction
- 578A/C pressure sensor circuit failure
- 579Insufficient A/C pressure change
- 585Power to A/C clutch over current
- 586A/C clutch circuit open
- 970Overdrive indicator lamp circuit malfunction
Network Communications
How to read Ford codes
- Find the self-test connector under the hood, usually at the firewall or on a front fender apron.
- Jumper the self-test input to signal return with a paperclip or a short wire.
- Key on, engine off. Count the check-engine flashes. Code 11 means the system passed.
- Start the engine and read the running self test the same way.
- Continuous memory codes come after a six second delay and a single half second flash. Look each code up below, then remove the jumper.
New to this? How to Read Ford EEC-IV Self-Test Codes walks through the test and what the numbers mean.