DTC P0037: Ho2S Heater Circuit Low: Testing
NOTE:
Ensure freeze frame data has been recorded. Check for service bulletins and on-line information.
- Turn ignition off. Disconnect O2 sensor. Check connectors for damaged terminals and corrosion. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, go to step 7 .
- Check resistance between sensor connector terminals. See OXYGEN SENSOR TERMINAL & RESISTANCE IDENTIFICATION
table. If resistance is okay, go to next step. If resistance is not okay, replace O2 sensor and go to step 7
.OXYGEN SENSOR TERMINAL & RESISTANCE IDENTIFICATION
Application Terminals Resistance (Ohms) Middle (Federal) A & B 16 Right Rear (California) C & D 14.2-18.8 - Turn ignition on. On California models, check voltage between O2 harness connector terminal "C" (Black/White wire) and ground. On Federal models, check voltage between O2 harness connector terminal "A" (Black/White wire) and ground. On all models, if battery voltage is present, go to next step. If battery voltage is not present, repair open circuit between sensor and relay and go to step 7 .
- Turn ignition off. Disconnect PCM connector. PCM is mounted to passenger floor, behind glove box. Check harness connector and PCM terminal No. 95 for damaged terminals and corrosion. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, go to step 7 .
- Check continuity between O2 sensor harness connector terminal (Light Green/Black wire) "B" (Federal) or "D" (California) and ground. If continuity is not present, go to next step. If continuity is present, repair short to ground on circuit between harness connector and PCM terminal No. 95. After repair, go to step 7 .
- Connect breakout box to harness connector. Leave PCM disconnected. Check continuity between O2 sensor harness connector terminal "B" (Federal) or "D" (California) and breakout box terminal No. 95. If continuity is present, go to next step. If continuity is not present, repair open on Light Green/Black wire between harness connector and PCM. After repair, go to next step.
- Reconnect all components. Using scan tool, clear DTC. Start engine and allow to reach operating temperature. Using scan tool, check for DTC P0037. If DTC P0037 is not pending, go to next step. If DTC P0037 is pending, replace PCM and go to next step.
- Perform after repair procedure. See AFTER REPAIR PROCEDURE . If no DTC is present, testing is complete. If any DTC is present, go to appropriate test for diagnosis and repair.