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. Clear the DTC with the HDS.
2. Test-drive the vehicle at speeds over 12 mph (20 km/h) in D through all five gears.
3. Turn the ignition switch to LOCK (0), and repeat the test-drive in step 2.
4. Monitor the OBD STATUS for P0718 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - 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.
NO - If the screen indicates FAILED, go to step 5. If the screen 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 the 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 at speeds over 12 mph (20 km/h) in D through all five gears.
9. Turn the ignition switch to LOCK (0), and repeat the test-drive in step 8.
10. Monitor the OBD STATUS for P0718 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - The problem has been corrected.
NO - If the screen indicates FAILED, go to step 11. If the screen 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 B (44P).
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 a short to ground in the wire between PCM connector terminal B39 and the input shaft (mainshaft) speed sensor connector, then go to step 24.
NO - Go to step 16.
16. Connect PCM connector B (44P).
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 - Go to step 23.
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 (44P).
22. Check for continuity between PCM connector terminal B39 and input shaft (mainshaft) speed sensor connector terminal No. 2.
Is there continuity?
YES - Go to step 31.
NO - Repair an open in the wire between PCM connector terminal B39 and the input shaft (mainshaft- speed sensor, then go to step 24.
23. Replace the input shaft (mainshaft) speed sensor.
24. Reconnect all connectors.
25. Turn the ignition switch to ON (II).
26. Clear the DTC with the HDS.
27. Test-drive the vehicle at speeds over 12 mph (20 km/h) in D through all five gears.
28. Turn the ignition switch to LOCK (0), and repeat the test-drive in step 27.
29. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0718 indicated?
YES - Check for poor connections or loose terminals at the input shaft (mainshaft) speed sensor and the PCM, then go to step 1.
NO - If Temporary DTC or DTC P0718 is not indicated, or if any other Temporary DTCs are indicated, go to step 30.
30. 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 Temporary DTC or DTCs were indicated on step 29, go to the indicated DTCs troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the input shaft (mainshaft) speed sensor and the PCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 27.
31. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
32. Test-drive the vehicle at speeds over 12 mph (20 km/h) in D through all five gears.
33. Turn the ignition switch to LOCK (0), and repeat the test-drive in step 32.
34. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0718 indicated?
YES - Check for poor connections or loose terminals at the input shaft (mainshaft) speed sensor and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 32. If the PCM was substituted, go to step 1.
NO - If Temporary DTC or DTC P0718 is not indicated, or if any other Temporary DTCs or DTCs are indicated, go to step 35.
35. 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 Temporary DTCs or DTCs were indicated on step 30, go to the indicated DTCs troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the input shaft (mainshaft) speed sensor and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 32. If the PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, go to step 32.