Possible Causes
| Possible Causes |
|---|
| (K99) O2 1/1 HEATER CONTROL CIRCUIT SHORTED TO VOLTAGE |
| (K99) O2 1/1 HEATER CONTROL CIRCUIT SHORTED TO GROUND |
| (K99) O2 1/1 HEATER CONTROL CIRCUIT OPEN OR HIGH RESISTANCE |
| (A15) FUSED ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE |
| OXYGEN SENSOR |
| ENGINE CONTROL MODULE (ECM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. See DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure