Retrieving Codes
- Perform diagnostic circuit check before diagnosing vehicle using self-diagnostic system. See appropriate DIAGNOSTIC CIRCUIT CHECK chart under DIAGNOSTIC CODE CHARTS.
- Ensure ignition switch is in the OFF position. Using a jumper wire, connect diagnostic terminal to the ground terminal. See Fig 1 . Connector is located in engine compartment. Turn ignition switch to the ON position. Read fault codes.
- If no fault codes are stored, CHECK ENGINE light will flash on and off rapidly until jumper wire is disconnected. Count the number of flashes and look for pauses in flashing to ensure no fault codes are overlooked. If fault codes are stored, code will flash 3 times starting with the lowest code.
FAULT CODE IDENTIFICATION
| Code | Circuit Affected | Probable Cause |
|---|---|---|
| 12 | No RPM Signal | No Signal For 2 Seconds |
| 13 | No RPM Signal | No Signal For 2 Seconds |
| 14 | Ignition Signal | No Signal |
| 21 | Oxygen Sensor | Open/Short Circuit |
| 22 | Coolant Temp. Sensor | Open/Short Circuit |
| 24 | Intake Air Temp. Sensor | Low Temp. Indicated |
| 25 | Oxygen Sensor | Lean Exhaust Indicated |
| 26 | Oxygen Sensor | Rich Exhaust Indicated |
| 27 | Sub-Oxygen Sensor (VIN 5-Calif.) | Open/Short Circuit |
| 31 | Mass Airflow Sensor (VIN 5) | Short Circuit |
| 31 | MAP Sensor (VIN 6) | Open/Short Circuit |
| 41 | Throttle Position Sensor Circuit (VIN 5) | Open/Short Circuit |
| 41 | Throttle Switch (VIN 6) | Incorrect Signal Voltage |
| 42 | Vehicle Speed Sensor | Incorrect Signal Voltage |
| 43 | No Crank Signal | No Signal From Starter |
| 51 | No A/C Signal | No Signal Present |
| 52 | Knock Sensor Signal (VIN 5) | Open/Short Circuit |
| 53 | Knock Control Signal (VIN 5) | Faulty ECM |
| 71 | EGR Temperature Sensor (Calif.) | Out Of Calibration |