Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
- Start the engine, and let it idle for 5 minutes or more.
- Check ECT SENSOR 1 in the DATA LIST with the HDS. Is about 10°F (-12°C) or less, or 4.45 V or more indicated? YES -Go to step 9 . NO -Go to step 3.
- Allow the engine to cool to 104°F (40°C) or less.
- Note the value of ECT SENSOR 1 and ECT SENSOR 2 in the DATA LIST with the HDS.
- Start the engine, and let it idle.
- Let the engine idle until ECT SENSOR 1 goes up 40°F (22°C) or more from the recorded temperature.
- Note the value of ECT SENSOR 2 in the DATA LIST with the HDS.
- Compare ECT SENSOR 2 and the recorded temperature. Did ECT SENSOR 2 change 17°F (9.5°C) or more? YES -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM. NO -Test the thermostat (see «THERMOSTAT TEST»(ref-243298-S00608961722006082300000) ). If the thermostat is OK, go to step 9. If you replace the thermostat, go to step 11 .
- Turn the ignition switch OFF.
- Replace ECT sensor 1 (see «ECT SENSOR 1 REPLACEMENT»(ref-298125-S01962212042008091500000) ).
- Turn the ignition switch ON (II).
- Reset the PCM with the HDS.
- Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(ref-243313-S13405059332006082300000) ).
- Allow the engine to cool to ambient temperature.
- Start the engine, and let it idle 20 minutes.
- Check for Temporary DTCs or DTCs with the HDS. Is DTC P0125 indicated? YES -Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM, then go to step 1 . NO -Go to step 17.
- Monitor the OBD STATUS for DTC P0125 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES -Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 16 , go to the indicated DTC's troubleshooting. NO -If the screen indicates FAILED, check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM, then go to step 1 . If the screen indicates NOT COMPLETED, go to step 14 .