| 93-95 4.3, 5.0, 5.7, 7.4L VIN Z, H, K, N |
| Flash Code |
Fault Location |
Probable Cause |
| 12 |
Start of diagnosis |
No engine speed (RPM) signal received |
| 13 |
Oxygen sensor (O2S)/heated oxygen sensor (HO2S) |
Wiring open circuit, O2S/HO2S, ECM |
| 14 |
Engine coolant temperature (ECT) sensor – high temperature indicated |
Wiring short circuit to ground, ECT sensor, ECM |
| 15 |
Engine coolant temperature (ECT) sensor – low temperature indicated |
Wiring open circuit, ECT sensor, ECM |
| 16 |
Vehicle speed sensor (VSS) buffer – signal low |
Wiring, VSS buffer, ECM |
| 17 |
Camshaft position (CMP) sensor – circuit malfunction |
Wiring, CMP sensor, mechanical fault, ECM |
| 21 |
Throttle position (TP) sensor – voltage high |
Wiring open circuit/short circuit to positive, TP sensor, ECM |
| 22 |
Throttle position (TP) sensor – voltage low |
Wiring open circuit/short circuit to ground, TP sensor, ECM |
| 23 |
Intake air temperature (IAT) sensor – low temperature |
Wiring open circuit, IAT sensor, ECM |
| 24 |
Vehicle speed sensor (VSS) |
Wiring open circuit/short circuit to ground, PROM, VSS, ECM |
| 25 |
Intake air temperature (IAT) sensor – high temperature |
Wiring short circuit to ground, IAT sensor, ECM |
| 28 |
Transmission range (TR) switch |
Wiring open circuit/short circuit to ground/short circuit to positive, TR switch, ECM |
| 31 |
Engine speed control system – malfunction |
Wiring, throttle valve motor, throttle valve control module, ECM |
| 32 |
Exhaust gas recirculation (EGR) solenoid |
Wiring open circuit/short circuit to ground, EGR valve, ECM |
| 33 |
Manifold absolute pressure (MAP) sensor – circuit malfunction |
Wiring open circuit/short circuit to positive, hose blocked/leaking, MAP sensor, ECM |
| 34 |
Manifold absolute pressure (MAP) sensor – circuit malfunction |
Wiring open circuit/short circuit to ground, MAP sensor, ECM |
| 35 |
Idle air control (IAC) valve |
Wiring, IAC valve, intake system leaking, fuel system, PCV valve, A/C system, mechanical fault, ECM |
| 36 |
Auxiliary idle air control valve |
Wiring, idle air control valve, vacuum pipes, ECM |
| 37 |
Brake pedal position (BPP) switch for torque converter clutch (TCC) |
Wiring open circuit/short circuit to ground, incorrectly adjusted BPP switch, BPP switch, ECM |
| 38 |
Brake pedal position (BPP) switch/ torque converter clutch (TCC) |
Wiring open circuit/short circuit to ground, supply wire, BPP switch, TCC switch, ECM |
| 39 |
Brake pedal position (BPP) switch – stuck OFF |
Wiring, BPP switch, ECM |
| 42 |
Ignition control module (ICM) – electronic spark timing (EST)/ignition control (IC)/bypass circuit malfunction |
Wiring open circuit/short circuit to ground, ICM, ECM |
| 43 |
Knock sensor (KS) |
Wiring open circuit/short circuit to ground/short to positive, KS, PROM, ECM |
| 44 |
Oxygen sensor (O2S)/heated oxygen sensor (HO2S) – mixture lean |
Wiring short circuit to ground, fuel pressure low, MAP sensor, misfire, fuel contamination, exhaust system leaking, O2S/HO2S, ECM |
| 45 |
Oxygen sensor (O2S)/heated oxygen sensor (HO2S) – mixture rich |
Fuel pressure high, injector(s) leaking, O2S contamination, EVAP canister purge valve, TP sensor, MAP sensor, EGR system, O2S/H2OS, ECM |
| 46 |
Immobilizer system, code – malfunction |
Incorrect key, ECM |
| 51 |
Engine control module (ECM) – PROM |
Insecure PROM, incorrect PROM, ECM |
| 52 |
System Voltage – high |
Alternator, jump started |
| 53 |
System Voltage – high |
Alternator |
| 54 |
Fuel pump circuit – voltage low |
Wiring open circuit/short circuit to ground, fuel pump relay, fuel pump, engine oil pressure warning lamp switch, ECM |
| 55 |
Engine control module (ECM) |
Ground wiring open circuit, insecure PROM, ECM |
| 58 |
Transmission fluid temperature (TFT) sensor – voltage low |
Wiring short circuit to ground, TFT sensor, ECM |
| 59 |
Transmission fluid temperature (TFT) sensor -voltage high |
Wiring open circuit, TFT sensor, ECM |
| 61 |
Oxygen sensor (O2S) |
O2S |
| 62 |
Transmission gear switch signal circuit |
Wiring open circuit/short circuit to ground, 2nd gear switch, 3rd gear switch, ECM |
| 66 |
Transmission shift solenoid (SS), 3rd-2nd – downshift malfunction |
Wiring, SS, ECM |
| 67 |
Torque converter clutch (TCC) – circuit malfunction |
Wiring, TCC solenoid, ECM |
| 68 |
Torque converter clutch (TCC) – slipping |
Wiring, TCC solenoid, transmission mechanical fault, ECM |
| 69 |
Torque converter clutch (TCC) solenoid – stuck ON |
Wiring open circuit/short circuit to ground, transmission internal wiring, TCC solenoid, transmission mechanical fault, ECM |
| 70 |
A/C refrigerant pressure sensor – voltage high |
Wiring open circuit/short circuit to positive, A/C refrigerant pressure sensor, ECM |
| 72 |
Vehicle Speed Sensor (VSS) |
Wiring open circuit/short circuit to ground, VSS, ECM |
| 73 |
Transmission fluid pressure (TFP) control solenoid – circuit malfunction |
Wiring, poor connection, TFP solenoid |
| 74 |
Transmission input shaft speed sensor – circuit malfunction |
Wiring, input shaft speed sensor, ECM |
| 75 |
System voltage, engine control module (ECM) – low |
Wiring, battery, alternator, ECM |
| 76 |
Exhaust gas recirculation (EGR) valve solenoid 2 |
Wiring open circuit/short circuit to ground, supply wire, EGR valve, ECM |
| 77 |
Exhaust gas recirculation (EGR) valve solenoid 3 |
Wiring open circuit/short circuit to ground, supply wire, EGR valve, ECM |
| 79 |
Transmission fluid temperature (TFT) – high |
Transmission mechanical fault, towing |
| 80 |
Torque converter clutch (TCC) – slipping |
Wiring open circuit/short circuit to ground, supply wire, transmission internal wiring, TCC solenoid, transmission mechanical fault, ECM |
| 81 |
Transmission shift solenoid (SS), 2nd-3rd – circuit malfunction |
Wiring, SS, ECM |
| 82 |
Transmission shift solenoid (SS), 1st-2nd – circuit malfunction |
Wiring, SS, ECM |
| 83 |
Torque converter clutch (TCC) solenoid, pulse width modulated – circuit malfunction |
Wiring, TCC solenoid, ECUM |
| 85 |
Transmission input/output shaft speed, ratio variation – out of range |
Wiring, input shaft speed sensor, output shaft speed sensor, mechanical fault |
| 86 |
Transmission input/output shaft speed, ratio variation – lower than expected |
Wiring, input shaft speed sensor, output shaft speed sensor, mechanical fault |
| 87 |
Transmission input/output shaft speed, ratio variation – out of range |
Wiring, input shaft speed sensor, output shaft speed sensor, mechanical fault |
| 90 |
Torque converter clutch (TCC) – stuck ON |
Wiring open circuit/short circuit to ground, transmission internal wiring, TCC solenoid, transmission mechanical fault, ECM |
| 96 |
Engine control module (ECM) – ignition supply voltage low |
Wiring open circuit, alternator, ECM |
| 98 |
Engine control module (ECM) – incorrectly coded |
ECM incorrectly coded, ECM |
| 99 |
Engine control module (ECM) – incorrectly coded |
ECM incorrectly coded, ECM |
