Possible Causes
| Possible Causes |
|---|
| INTERMITTENT DTC |
| (K99) O2 1/1 HEATER CONTROL CIRCUIT OPEN OR HIGH RESISTANCE |
| (Z42) GROUND CIRCUIT OPEN OR HIGH RESISTANCE |
| 1/1 O2 SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding.