Possible Causes
| POSSIBLE CAUSES |
|---|
| O2 1/1 SIGNAL CIRCUIT SHORTED TO GROUND |
| O2 1/1 RETURN CIRCUIT SHORTED TO GROUND |
| O2 1/1 SIGNAL CIRCUIT SHORTED TO THE O2 1/1 RETURN CIRCUIT |
| O2 1/1 SIGNAL CIRCUIT SHORTED TO THE GROUND CIRCUIT |
| OXYGEN SENSOR 1/1 |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .