DTC Troubleshooting

DTC Troubleshooting: P1188

DTC P1188:

FTT Sensor Circuit High Voltage

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

1. Turn the ignition switch to ON (II).

2. Check the FTT SENSOR in the DATA LIST with the HDS.

Is about -40 °F (-40 °C) or less, or 4.92 V or more indicated?

YES -

Go to step 3.

NO -

Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the FTT sensor and the PCM.�

3. Turn the ignition switch to LOCK (0).

4. Disconnect the FTT sensor 2P connector.

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





6. Turn the ignition switch to ON (II).

7. Check the FTT SENSOR in the DATA LIST with the HDS.

Is about -40 °F (-40 °C) or less, or 4.92 V or more indicated?

YES -

Go to step 8.

NO -

Go to step 22.

8. Turn the ignition switch to LOCK (0).

9. Remove the jumper wire from the FTT sensor 2P connector.

10. Turn the ignition switch to ON (II).

11. Measure the voltage between FTT sensor 2P connector terminal No. 2 and body ground.





Is there about 5 V?

YES -

Go to step 12.

NO -

Go to step 17.

12. Turn the ignition switch to LOCK (0).

13. Jump the SCS line with the HDS.

14. Disconnect PCM connector A (44P).

15. Connect FTT sensor 2P connector terminal No. 1 to body ground with a jumper wire.






16. Check for continuity between PCM connector terminal A9 and body ground.





Is there continuity?

YES -

Go to step 29.

NO -

Repair open in the wire between the PCM (A9) and the FTT sensor, then go to step 24.

17. Turn the ignition switch to LOCK (0).

18. Jump the SCS line with the HDS.

19. Disconnect PCM connector A (44P).

20. Connect FTT sensor 2P connector terminal No. 2 to body ground with a jumper wire.






21. Check for continuity between PCM connector terminal A32 and body ground.





Is there continuity?

YES -

Go to step 29.

NO -

Repair open in the wire between the PCM (A32) and the FTT sensor, then go to step 24.

22. Turn the ignition switch to LOCK (0).

23. Replace the FTT sensor Service and Repair.

24. Reconnect all connectors.

25. Turn the ignition switch to ON (II).

26. Reset the PCM with the HDS.

27. Do the PCM idle learn procedure ECM/PCM Idle Learn Procedure.

28. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P1188 indicated?

YES -

Check for poor connections or loose terminals at the FTT sensor and the PCM, then go to step 1.

NO -

Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.�

29. Reconnect all connectors.

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

31. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P1188 indicated?

YES -

Check for poor connections or loose terminals at the FTT sensor and the PCM. If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to step 1.

NO -

If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.�