Transmission
DTC P0718: Input Shaft (Mainshaft) Speed Sensor Intermittent FailureNOTE:
^ Before you troubleshoot, record all freeze data and any on-board snapshot, and review General Troubleshooting Information.
^ 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 for several minutes in the D position 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 result 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 OFF.
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. Connect the input shaft (mainshaft) speed sensor connector.
7. Test-drive the vehicle for several minutes in the D position through all five gears.
8. Monitor the OBD status for P0718 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the result indicate FAILED?
YES - Go to step 9.
NO - Troubleshooting is complete. If the HDS indicates NOT COMPLETED, return to step 7 and recheck.
9. Turn the ignition switch OFF.
10. Jump the SCS line with the HDS.
11. Disconnect PCM connector A (31P).
12. Check for continuity between PCM connector terminal A8 and body ground, and between terminal A9 and body ground.
Is there continuity?
YES - Go to step 13.
NO - Repair open in the wires between PCM connector terminals A8, A9, and ground (G101), or repair poor ground (G101), then go to step 29.
13. Connect PCM connector A (31P).
14. Disconnect the input shaft (mainshaft) speed sensor connector.
15. Turn the ignition switch ON (II).
16. Measure voltage between input shaft (mainshaft) speed sensor connector terminal No. 1 and body ground.
Is there about 5 V?
YES - Go to step 17.
NO - Go to step 25.
17. Turn the ignition switch OFF.
18. Disconnect PCM connector C (22P).
19. Check for continuity between input shaft (mainshaft) speed sensor connector terminal No. 2 and body ground.
Is there continuity?
YES - Repair short to body ground in the wire between PCM connector terminal C19 and the input shaft (mainshaft) speed sensor connector, then go to step 29.
NO - Go to step 20.
20. Connect PCM connector C (22P).
21. Turn the ignition switch ON (II).
22. Measure 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, then go to step 29.
NO - Go to step 23.
23. Turn the ignition switch OFF.
24. Check for continuity between PCM connector terminal C19 and input shaft (mainshaft) speed sensor connector terminal No. 2.
Is there continuity?
YES - Go to step 32.
NO - Repair open in the wire between PCM connector terminal C19 and the input shaft (mainshaft) speed sensor, then go to step 29.
25. Measure voltage between PCM connector terminals A20 and A9.
Is there about 5 V?
YES - Repair open in the wire between the input shaft (mainshaft) speed sensor and PCM connector terminal A20, then go to step 29.
NO - Go to step 26.
26. Turn the ignition switch OFF.
27. Disconnect the PCM connector A (31P).
28. Check for continuity between PCM connector terminal A20 and body ground.
Is there continuity?
YES - Repair short to body ground in the wire between the input shaft (mainshaft) speed sensor and PCM connector terminal A20, then go to step 29.
NO - Go to step 32.
29. Clear the DTC with the HDS.
30. Test-drive the vehicle for several minutes in the D position through all five gears.
31. Monitor the OBD status for P0718 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the result indicate PASSED?
YES - Troubleshooting is complete.
NO - Check for poor connections or loose terminals at the input shaft (mainshaft) speed sensor and the PCM, then go to step 1.
32. Update the PCM if it does not have latest software, or substitute a known-good PCM.
33. Test-drive the vehicle for several minutes in the D position through all five gears.
34. Monitor the OBD status for P0718 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the result indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM.
NO - If the PCM was updated and screen indicates FAILED, substitute a known-good PCM, then go to step 33. If the PCM was substituted, check for poor connections or loose terminals at the input shaft (mainshaft) speed sensor and the PCM, then go to step 1 and recheck. If the screen indicates NOT COMPLETED, go to step 33.