Possible Causes
| Possible Causes |
|---|
| (K399) O2 SENSOR 2/2 HEATER CONTROL CIRCUIT SHORTED TO GROUND |
| EXCESSIVE RESISTANCE IN THE (K399) O2 SENSOR 2/2 HEATER CONTROL CIRCUIT |
| 2/2 O2 SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding.