Possible Causes
| Possible Causes |
|---|
| (K199) O2 2/1 HEATER CONTROL CIRCUIT SHORTED TO VOLTAGE |
| (K199) O2 2/1 HEATER CONTROL CIRCUIT OPEN |
| EXCESSIVE RESISTANCE IN THE (Z902) GROUND CIRCUIT |
| 2/1 OXYGEN SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to *PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .