Possible Causes
| POSSIBLE CAUSES |
|---|
| HIGH RESISTANCE IN THE (K79) O2 SENSOR 1/1 HEATER CONTROL CIRCUIT |
| HIGH RESISTANCE IN THE (Z904) GROUND CIRCUIT |
| OXYGEN SENSOR 1/1 |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE . .