| Various Models |
|---|
| Trouble Code | Fault Location | Probable Cause |
| 12 | Start of diagnosis | No engine speed (RPM) signal received |
| 14 | Engine coolant temperature (ECT) sensor -voltage low | Wiring, ECT sensor, ECM |
| 15 | Engine coolant temperature (ECT) sensor -voltage high | Wiring open circuit, ECT sensor, ECM |
| 16 | Transmission output speed sensor -signal low | Wiring, transmission output speed sensor, ECM |
| 21 | Fuel lever position sensor -voltage high | Wiring open circuit/short circuit to positive, fuel lever position sensor, ECM |
| 22 | Fuel lever position sensor -voltage low | Wiring open circuit/short circuit to ground, fuel lever position sensor, ECM |
| 23 | Fuel lever position sensor -signal out of range | Adjustment, wiring, fuel lever position sensor |
| 24 | Vehicle speed sensor (VSS) -no signal | Wiring, VSS, ECM |
| 31 | Manifold absolute pressure (MAP) sensor -voltage low | Wiring open circuit/short circuit to ground, MAP sensor, ECM |
| 32 | Exhaust gas recirculation (EGR) solenoid | Wiring, poor connections, EGR valve, ECM |
| 33 | Manifold absolute pressure (MAP) sensor -voltage high | Wiring, hose blocked/leaking, MAP sensor, ECM |
| 51 | Engine control module (ECM), PROM -malfunction | Poor connections, incorrect programming, ECM |
| 52 | Engine control module (ECM) -malfunction | ECM |
| 53 (1992) | Engine control module (ECM), sensor supply voltage -circuit malfunction | Wiring, poor connections, MAP sensor |
| 53 (1993) | System voltage -high | Alternator |
| 55 | Engine control module (ECM) -malfunction | ECM |
