Possible Causes
| Possible Causes |
|---|
| (K99) O2 1/1 HEATER CONTROL CIRCUIT OPEN |
| (Z43) O2 1/1 HEATER GROUND CIRCUIT OPEN |
| (K99) O2 1/1 HEATER CONTROL CIRCUIT SHORTED TO VOLTAGE |
| 1/1 O2 SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
WARNING:
On vehicles equipped with the high voltage system, you must thoroughly read and follow all High Voltage Safety procedures. In addition, before performing any diagnostic or service procedure near a high voltage component, you must perform the High Voltage Power Down. Failure to follow these instructions may result in possible serious or fatal injury. Refer to Electrical - Engine Systems/Battery System - Warning
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .