Possible Causes
| Possible Causes |
|---|
| (K902) O2 RETURN UPSTREAM CIRCUIT SHORTED TO GROUND |
| (K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO GROUND |
| (K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO THE (K902) O2 RETURN UPSTREAM CIRCUIT |
| (K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO THE (Z42) HEATER GROUND CIRCUIT |
| 2/1 O2 SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .