Possible Causes
| Possible Causes |
|---|
| (K99) O2 SENSOR 1/1 HEATER CONTROL CIRCUIT SHORTED TO GROUND |
| O2 SENSOR |
| PCM |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .