DTC Troubleshooting

DTC Troubleshooting: P0718 (15)

DTC P0718: Input Shaft (Mainshaft) Speed Sensor Intermittent Failure

NOTE:

- Before you troubleshoot, record all freeze data and any on-board snapshot, and review General Troubleshooting Information. How to Troubleshoot A/T Systems

- This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.

1. Clear the DTC with the HDS.

2. Test-drive the vehicle at speeds over 12 mph (20 km/h) in D through all five gears.

3. Monitor the OBD STATUS for P0718 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.

Does the HDS indicate FAILED?
YES - Go to step 4.

NO - If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the input shaft (mainshaft) speed sensor and the PCM. If the HDS indicates NOT COMPLETED, return to step 2 and recheck.


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

5. Disconnect the input shaft (mainshaft) speed sensor connector, and inspect the connector and connector terminals to be sure they are making good contact.

Are the connector terminals OK?
YES - Go to step 6.

NO - Repair the connector terminals, then go to step 6.


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

7. Jump the SCS line with the HDS.

8. Disconnect PCM connectors B (49P) and C (49P).

9. Check for continuity between PCM connector terminals B41 and body ground, and between C41 and body ground.

Is there continuity?
YES - Go to step 10.

NO - Repair open in the wires between PCM connector terminals B41, C41 and ground (G101), or repair poor ground (G101), then go to step 31.






10. Connect PCM connectors B (49P) and C (49P).

11. Disconnect the input shaft (mainshaft) speed sensor connector.

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

13. Measure the voltage between input shaft (mainshaft) speed sensor connector terminal No. 1 and body ground.

Is there about 5 V?
YES - Go to step 14.

NO - Go to step 23.






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

15. Disconnect PCM connector B (49P).

16. Check for continuity between input shaft (mainshaft) speed sensor connector terminal No. 2 and body ground.

Is there continuity?
YES - Repair short in the wire between PCM connector terminal B37 and the input shaft (mainshaft) speed sensor connector, then go to step 31.

NO - Go to step 17.






17. Connect PCM connector B (49P).

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

19. Measure the voltage between input shaft (mainshaft) speed sensor connector terminal No. 2 and body ground.

Is there about 5 V?
YES - Replace the input shaft (mainshaft) speed sensor, A/T Input Shaft (Mainshaft) Speed Sensor Replacement then go to step 31.

NO - Go to step 20.






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

21. Disconnect PCM connector B (49P).

22. Check for continuity between PCM connector terminal B37 and input shaft (mainshaft) speed sensor connector terminal No. 2.

Is there continuity?
YES - Go to step 26.

NO - Repair open in the wire between PCM connector terminal B37 and the input shaft (mainshaft) speed sensor, then go to step 31.






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

24. Disconnect PCM connector C (49P).

25. Check for continuity between PCM connector terminal C12 and input shaft (mainshaft) speed sensor connector terminal No. 1.

Is there continuity?
YES - Go to step 26.

NO - Repair open in the wire between PCM connector terminal C12 and the input shaft (mainshaft) speed sensor, then go to step 31.






26. Reconnect all connectors.

27. Update the A/T software in the PCM if it does not have the latest software, Service and Repair or substitute a known-good PCM. How to Troubleshoot A/T Systems

28. Test-drive the vehicle at speeds over 12 mph (20 km/h) in D through all five gears.

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

Is DTC P0718 indicated?
YES - If the PCM was updated, substitute a known-good PCM, How to Troubleshoot A/T Systems then recheck. If the PCM was substituted, go to step 1.

NO - Go to step 30.


30. Monitor the OBD STATUS for P0718 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.

Does the HDS indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. Service and Repair If any other DTCs were indicated on step 29, go to the indicated DTC's troubleshooting.

NO - If the HDS indicates FAILED, check for poor connections and loose terminals at the input shaft (mainshaft) speed sensor and the PCM. If the PCM was updated, substitute a known-good PCM, How to Troubleshoot A/T Systems then recheck. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, return to step 28 and recheck.


31. Clear the DTC with the HDS.

32. Test-drive the vehicle at speeds over 12 mph (20 km/h) in D through all five gears.

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

Is DTC P0718 indicated?
YES - Check for poor connections and loose terminals at the input shaft (mainshaft) speed sensor and the PCM, then go to step 1.

NO - Go to step 34.


34. Monitor the OBD STATUS for P0718 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.

Does the HDS indicate PASSED?
YES - Troubleshooting is complete. If any other DTCs were indicated on step 33, go to the indicated DTC's troubleshooting.

NO - If the HDS indicates FAILED, check for poor connections and loose terminals at the input shaft (mainshaft) speed sensor and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, return to step 32 and recheck.