Automatic 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. Turn the ignition switch to ON (II).
2. Clear the DTC: with the HDS.
3. Test-drive the vehicle at speeds over 12 mph (20 km/h) with the shift lever in D, and let the transmission shift through all five gears.
4. Turn the ignition switch to LOCK (0). Repeat the test-drive in step 3, then go to step 5.
5. Monitor the OBD STATUS for P0718 in the DTCs MENU with the HDS.
Does the screen indicate FAILED?
YES - Go to step 6.
NO - 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 screen indicates NOT COMPLETED, go to step 3.
6. Turn the ignition switch to LOCK (0).
7. 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 8.
NO - Repair the connector terminals, then go to step 8.
8. Connect the input shaft (mainshaft) speed sensor connector.
9. Test-drive the vehicle at speeds over 12 mph (20 km/h) with the shift lever in D, and let the transmission shift through all five gears.
10. Turn the ignition switch to LOCK (0). Repeat the test-drive in step 9, then go to step 11.
11. Monitor the OBD STATUS for P0718 in the DTCs MENU with the HDS.
Does the screen indicate FAILED?
YES - Go to step 12.
NO - If the screen indicated PASSED, troubleshooting is complete. If the screen indicates NOT COMPLETED, go to step 9.
12. Turn the ignition switch to LOCK (0).
13. Jump the SCS line with the HDS.
14. Disconnect PCM connector D (17P).
15. Disconnect the input shaft (mainshaft) speed sensor connector.
16. 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 D8 and the input shaft (mainshaft) speed sensor, then go to step 23.
NO - Go to step 17.
17. Connect PCM connector D (17P).
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, then go to step 23.
NO - Go to step 20.
20. Turn the ignition switch to LOCK (0).
21. Disconnect PCM connector D (17P).
22. 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 30.
NO - Repair open in the wire between PCM connector terminal D8 and the input shaft (mainshaft) speed sensor, then go to step 23.
23. Reconnect all connectors.
24. Turn the ignition switch to ON (II).
25. Clear the DTC with the HDS.
26. Test-drive the vehicle at speeds over 12 mph (20 km/h) with the shift lever in D, and let the transmission shift through all five gears.
27. Turn the ignition switch to LOCK (0). Repeat the test-drive in step 26, then go to step 28.
28. Check for DTCs with the HDS.
Is DTC P0718 indicated?
YES - Check for poor connections or loose terminals between the input shaft (mainshaft) speed sensor and the PCM, then go to step 1.
NO - Go to step 29.
29. Monitor the OBD STATUS for P0718 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other DTCs were indicated in step 28, go to the indicated DTC's troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals between the input shaft (mainshaft) speed sensor and the PCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 26.
30. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
31. Test-drive the vehicle at speeds over 12 mph (20 km/h) with the shift lever in D, and let the transmission shift through all five gears.
32. Turn the ignition switch to LOCK (0). Repeat the test-drive in step 31, then go to step 33.
33. Check for DTCs with the HDS.
Is DTC P0718 indicated?
YES - Check for poor connections or loose terminals between the input shaft (mainshaft) speed sensor and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 31. If the PCM was substituted, go to step 1.
NO - Go to step 34.
34. Monitor the OBD STATUS for P0718 in the DTCs MENU with the HDS.
Does the screen 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 in step 33, go to the indicated DTC's troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals between the input shaft (mainshaft) speed sensor and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 31. If the PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, go to step 31.