Possible Causes
| Possible Causes |
|---|
| ANY O2 SENSOR RETURN CIRCUIT SHORTED TO VOLTAGE |
| ANY O2 SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE |
| ANY OXYGEN SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .