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 with the HDS, 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 with the shift lever in D, and let the transmission shift through all five gears at speeds above 12 mph (20 km/h). Slow down and stop the wheels.

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 - 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 28.


6. Jump the SCS line with the HDS.

7. Disconnect PCM connector C (49P).

8. Check for continuity between PCM connector terminal C44 and body ground, and between terminal C48 and body ground.

Is there continuity?
YES - Go to step 9.

NO - Repair open in the wires between PCM connector terminals C44, C48 and ground (G101), or repair poor ground (G101), then go to step 28.






9. Connect PCM connector C (49P).

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

11. 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 12.

NO - Go to step 19.






12. 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 (A/T) then go to step 28.

NO - Go to step 13.






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

14. Jump the SCS line with the HDS.

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 B18 and the input shaft (mainshaft) speed sensor connector, then go to step 28.

NO - Go to step 17.






17. Check for continuity between PCM connector terminal B18 and input shaft (mainshaft) speed sensor connector terminal No. 2.

Is there continuity?
YES - Go to step 18.

NO - Repair open in the wire between PCM connector terminal B18 and the input shaft (mainshaft) speed sensor, then go to step 28.






18. Check for continuity between PCM connector terminal B34 and input shaft (mainshaft) speed sensor connector terminal No. 3.

Is there continuity?
YES - Go to step 23.

NO - Repair open in the wire between PCM connector terminal B34 and the input shaft (mainshaft) speed sensor, then go to step 28.






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

20. Jump the SCS line with the HDS.

21. Disconnect PCM connector B (49P).

22. Check for continuity between PCM connector terminal B19 and input shaft (mainshaft) speed sensor connector terminal No. 1.

Is there continuity?
YES - Go to step 23.

NO - Repair open in the wire between PCM connector terminal B19 and the input shaft (mainshaft) speed sensor, then go to step 28.






23. Reconnect all connectors.

24. Update the A/T software in the PCM if it does not have the latest software, ECM/PCM Update or substitute a known-good PCM. Initial Inspection and Diagnostic Overview

25. Test-drive the vehicle with the shift lever in D, and let the transmission shift through all five gears at speeds above 12 mph (20 km/h). Slow down and stop the wheels.

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

Is DTC P0718 indicated?
YES - If the PCM was updated, substitute a known-good PCM, Initial Inspection and Diagnostic Overview then recheck. If the PCM was substituted, go to step 1.

NO - Go to step 27.


27. 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 26, go to the indicated DTC's troubleshooting.

NO - 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, Initial Inspection and Diagnostic Overview then recheck. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, return to step 25 and recheck.


28. Reconnect all connectors.

29. Clear the DTC with the HDS.

30. Test-drive the vehicle with the shift lever in D, and let the transmission shift through all five gears at speeds above 12 mph (20 km/h). Slow down and stop the wheels.

31. Check for Pending or Confirmed 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 32.


32. 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 31, go to the indicated DTC's troubleshooting.

NO - 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 30 and recheck.