P0718
DTC P0718: Mainshaft Speed Sensor Intermittent FailureNOTE:
^ Record all freeze data and review General Troubleshooting Information before you troubleshoot.
^ 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 position in all five gears.
3. Check the OBD STATUS in DTCs MENU for a pass/fail test of code P0718.
Did the result indicate a fail?
YES - Go to step 4.
NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the mainshaft speed sensor and PCM. If the tester indicates NOT COMPLETE, return to step 2 and recheck.
4. Turn the ignition switch OFF.
5. Disconnect the 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 mainshaft speed sensor connector.
7. Test-drive the vehicle for several minutes, and check the ODD STATUS in DTCs MENU for a pass/fail test of code P0718.
Did the result indicate a fail?
YES - Go to step 8.
NO - The problem has been corrected. If the tester indicates NOT COMPLETE, return to step 7 and recheck.
8. Turn the ignition switch OFF.
9. Jump the SCS line with the HDS.
10. Disconnect PCM connector C (22P).
11. Disconnect the mainshaft speed sensor connector.
12. Check for continuity between mainshaft speed sensor connector terminal No. 2 and body ground.
Is there continuity?
YES - Repair short to ground in the wire between PCM connector terminal C19 and the mainshaft speed sensor connector, then go to step 19.
NO - Go to step 13.
13. Connect PCM connector C (22P).
14. Turn the ignition switch ON (II).
15. Measure the voltage between mainshaft speed sensor connector terminal No. 2 and body ground.
Is there about 5 V?
YES - Replace the mainshaft speed sensor, then go to step 19.
NO - Go to step 16.
16. Turn the ignition switch OFF.
17. Disconnect PCM connector C (22P).
18. Check for continuity between PCM connector terminal C19 and mainshaft speed sensor connector terminal No. 2.
Is there continuity?
YES - Update the PCM if it doe s not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM.
NO - Repair open in the wire between PCM connector terminal C19 and the mainshaft speed sensor, then go to step 19.
19. Clear the DTC with the HDS.
20. Test-drive the vehicle for several minutes in the [D] position in all five gears.
21. Check the OBD STATUS in DTCs MENU for a pass/fail test of code P071B.
Did the result indicate a pass?
YES - The problem has been corrected.
NO - Return to step 1 and recheck.