Possible Causes
| Possible Causes |
|---|
| O2 1/1 PUMP CELL CURRENT TRIM CIRCUIT OPEN OR HIGH RESISTANCE |
| O2 SENSOR 2/1 |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .