Self-Diagnostic System Check
- Locate ALDL diagnostic connector near ECM in right kick panel. Using a jumper wire, jump between terminals "A" and "B". See Fig 1 . Turn ignition on, but do not start engine. SES light will begin to flash diagnostic code 12 indicating the system is working.
- Code 12 will flash 3 times, then any additional code will flash 3 times and continue to cycle in this sequence. A code 12 consists of one flash, a short pause and 2 flashes. See Fig 2 .
- To clear codes, remove the battery cable for 30 seconds.
DIAGNOSTIC CODES
| Code | Condition |
|---|---|
| Code 12 | No distributor reference pulse to ECM. |
| Code 13 | Oxygen (O2) sensor ckt is open causing lean condition. |
| Code 14 | Coolant Temperature Sensor (CTS) voltage signal low. |
| Code 15 | Coolant Temperature Sensor (CTS) voltage signal high. |
| Code 21 | Throttle Position Sensor (TPS) voltage signal high. |
| Code 22 | Throttle Position Sensor (TPS) voltage signal low. |
| Code 24 | Vehicle Speed Sensor (VSS) malfunction. |
| Code 33 | Manifold Absolute Pressure (MAP) sensor voltage signal high. |
| Code 34 | Manifold Absolute Pressure (MAP) sensor voltage signal low. |
| Code 35 | Idle Speed Error |
| Code 42 | Electronic Spark Timing (EST) malfunction. |
| Code 43 | Detonation sensor malfunction. |
| Code 44 | Lean exhaust indication. |
| Code 45 | Rich exhaust indication. |
| Code 51 | MEM-CAL failure. |
| Code 53 | Charging system rate too high. |