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 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 - If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals between the input shaft (mainshaft) speed sensor and the PCM. If the HDS indicates NOT COMPLETED, go to step 2.


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 30.


6. Connect the input shaft (mainshaft) speed sensor connector.

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 body ground (G101), or repair poor body ground (G101), then go to step 30.






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 22.






14. 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 30.

NO - Go to step 15.






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

16. Jump the SCS line with the HDS.

17. Disconnect PCM connector B (49P).

18. 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 30.

NO - Go to step 19.






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 B37 and input shaft (mainshaft) speed sensor connector terminal No. 2.

Is there continuity?
YES - Go to step 27.

NO - Repair open in the wire between PCM connector terminal B37 and the input shaft (mainshaft) speed sensor, then go to step 32.






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

24. Jump the SCS line with the HDS.

25. Disconnect PCM connector C (49P).

26. 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 27.

NO - Repair open in the wire between PCM connector terminal C12 and the input shaft (mainshaft) speed sensor, then go to step 32.






27. Reconnect all connectors.

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

29. 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.

30. Check for Temporary DTCs or 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 31.


31. 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 30, go to the indicated DTC's troubleshooting.

NO - If the HDS indicates FAILED, check for poor connections and loose terminals between 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, go to step 29.


32. Reconnect all connectors.

33. Clear the DTC with the HDS.

34. 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.

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

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

NO - Go to step 36.


36. 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 35, go to the indicated DTC's troubleshooting.

NO - If the HDS indicates FAILED, check for poor connections and loose terminals between the input shaft (mainshaft) speed sensor and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, go to step 34.