DTC Troubleshooting
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 with the shift lever in D, and let the transmission shift through all five gears at speeds over 12 mph (20 km/h) for several minutes. Slow down and stop the wheels.
3. Turn the ignition switch to LOCK (0). Repeat step 2, then go to step 4.
4. 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 5.
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.
5. Turn the ignition switch to LOCK (0).
6. 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 7.
NO - Repair the connector terminals, then go to step 7.
7. Connect the input shaft (mainshaft) speed sensor connector.
8. Test-drive the vehicle with the shift lever in D, and let the transmission shift through all five gears at speeds over 12 mph (20 km/h) for several minutes. Slow down and stop the wheels.
9. Turn the ignition switch to LOCK (0). Repeat step 8, then go to step 10.
10. 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 11.
NO - The troubleshooting is complete. If the HDS indicates NOT COMPLETED, return to step 8 and recheck.
11. Turn the ignition switch to LOCK (0).
12. Jump the SCS line with the HDS.
13. Disconnect PCM connector D (17P).
14. Disconnect the input shaft (mainshaft) speed sensor connector.
15. 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 D8 and the input shaft (mainshaft) speed sensor connector, then go to step 28.
NO - Go to step 16.
16. Connect PCM connector D (17P).
17. Turn the ignition switch to ON (II).
18. 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, then go to step 28.
NO - Go to step 19.
19. Turn the ignition switch to LOCK (0).
20. Disconnect PCM connector D (17P).
21. Check for continuity between PCM connector terminal D8 and input shaft (mainshaft) speed sensor connector terminal No. 2.
Is there continuity?
YES - Go to step 22.
NO - Repair open in the wire between PCM connector terminal D8 and the input shaft (mainshaft) speed sensor, then go to step 28.
22. Reconnect all connectors.
23. Update the A/T software in the PCM if it does not have the latest software, or substitute a known-good PCM.
24. Test-drive the vehicle with the shift lever in D, and let the transmission shift through all five gears at speeds over 12 mph (20 km/h) for several minutes. Slow down and stop the wheels.
25. Turn the ignition switch to LOCK (0). Repeat step 24, then go to step 26.
26. Check for DTC(s) in the DTCs/Freeze Data in A/T Mode Menu with the HDS.
Is DTC P0718 indicated?
YES - If the PCM was updated, substitute a known-good PCM, 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. 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, then recheck. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, return to step 24 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 over 12 mph (20 km/h) for several minutes. Slow down and stop the wheels.
31. Turn the ignition switch to LOCK (0). Repeat step 30, then go to step 32.
32. Check for DTC(s) in the DTCs/Freeze Data in A/T Mode Menu 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 33.
33. 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 32, 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.