DTC Troubleshooting: P0118 (6)

DTC P0118:  ECT Sensor 1 Circuit High Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

1.Turn the ignition switch ON (II).

2.Check ECT SENSOR 1 in the DATA LIST with the HDS.

Is about -40 °C (-40 °F) or less, or 4.90 V or higher indicated?


YES - Go to 3.


NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1 and the ECM/PCM.n


3.Turn the ignition switch OFF.

4.Disconnect ECT sensor 1 2P connector.

5.Connect ECT sensor 1 2P connector terminals No. 1 and No. 2 with a jumper wire.

 

6.Turn the ignition switch ON (II).

7.Check ECT SENSOR 1 in the DATA LIST with the HDS.

Is about -40 °C (-40 °F) or less, or 4.90 V or higher indicated?


YES - Go to 8.


NO - Go to 20.


8.Turn the ignition switch OFF.

9.Remove the jumper wire from ECT sensor 1 2P connector.

10.Turn the ignition switch ON (II).

11.Measure voltage between ECT sensor 1 2P connector terminal No. 2 and body ground.

 

Is there about 5 V?


YES - Go to 12.


NO - Go to 16.

12.Turn the ignition switch OFF.

13.Jump the SCS line with the HDS.

14.Disconnect ECM/PCM connector B (44P).

15.Check for continuity between ECT sensor 1 2P connector terminal No. 1 and ECM/PCM connector terminal B33.

 

Is there continuity?


YES - Go to 27.


NO - Repair open in the wire between the ECM/PCM (B33) and ECT sensor 1, then go to 22.

16.Turn the ignition switch OFF.

17.Jump the SCS line with the HDS.

18.Disconnect ECM/PCM connector B (44P).

19.Check for continuity between ECT sensor 1 2P connector terminal No. 2 and ECM/PCM connector terminal B23.

 

Is there continuity?


YES - Go to 27.


NO - Repair open in the wire between the ECM/PCM (B23) and ECT sensor 1, then go to 22.

20.Turn the ignition switch OFF.

21.Replace ECT sensor 1.

22.Reconnect all connectors.

23.Turn the ignition switch ON (II).

24.Reset the ECM/PCM with the HDS.

25.Do the ECM/PCM idle learn procedure.

26.Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0118 is indicated, check for poor connections or loose terminals at ECT sensor 1 and the ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - Troubleshooting is complete.n


27.Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.

28.Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0118 is indicated, check for poor connections or loose terminals at ECT sensor 1 and the ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM.n