Possible Causes
| Possible Causes |
|---|
| O2 SENSOR 1/1 SIGNAL CIRCUIT SHORTED TO GROUND |
| O2 SENSOR 1/1 RETURN CIRCUIT SHORTED TO GROUND |
| O2 SENSOR 1/1 POSITIVE CURRENT CONTROL CIRCUIT SHORTED TO GROUND |
| O2 SENSOR 1/1 PUMP CELL CURRENT ADJUST CIRCUIT SHORTED TO GROUND |
| O2 SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to STANDARD PROCEDURE .