P0118
DTC P0118: ECT Sensor Circuit High Voltage1. Turn the ignition switch ON (II).
2. Check the ECT with the HDS or a scan tool.
Is -4 °F (-20 °C) or less or 5 V indicated?
YES - Go to step 3.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the ECT sensor and at the ECM/PCM.
3. Turn the ignition switch OFF.
4. Disconnect the ECT sensor 2P connector.
5. Connect ECT sensor 2P connector terminals No.1 and No.2 with a jumper wire.
6. Turn the ignition switch ON (II).
7. Check the ECT with the HDS or a scan tool.
Is -4 °F (-20 °C) or less, or 5 V indicated?
YES - Go to step 8.
NO - Replace the ECT sensor.
8. Turn the ignition switch OFF.
9. Remove the jumper wire.
10. Turn the ignition switch ON (II).
11. Measure voltage between ECT sensor 2P connector terminal No.2 and body ground.
Is there about 5 V?
YES - Go to step 12.
NO - Go to step 16.
12. Turn the ignition switch OFF.
13. Disconnect ECM/PCM connector A (31 P).
14. Connect ECT sensor 2P connector terminal No.1 to body ground with a jumper wire.
15. Check for continuity between ECM/PCM connector terminal A10 and body ground.
Is there continuity?
YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Repair open in the wire between the ECM/PCM (A10) and the IAT sensor.
16. Connect ECM/PCM connector terminals A10 and B8 with a jumper wire.
17. Turn the ignition switch ON (II).
18. Check the ECT with the HDS or a scan tool.
Is -4 °F (-20 °C) or less or 5 V indicated?
YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Repair open in the wire between the ECM/PCM (B8) and the ECT sensor.