P0979
DTC P0979: Short in Shift Solenoid Valve C CircuitNOTE:
^ 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 D position through all five gears.
3. Check that DTC P0979 recurs.
Is DTC P0979 indicated?
YES - Go to step 7.
NO - Go to step 4.
4. Choose Shift Solenoid C in Miscellaneous Test Menu, and test the shift solenoid valve C with the HDS.
Is the system normal?
YES - Go to step 5.
NO - Go to step 7.
5. Test-drive the vehicle for several minutes in the D position through all five gears.
6. Monitor the OBD status for P0979 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the result indicate FAILED?
YES - Go to step 7.
NO - If the tester indicates PASSED, intermittent failure, the system is OK at this time. Check the SH C (GRN) wire for an intermittent short to ground between shift solenoid valve C and the PCM. If the tester indicates NOT COMPLETED, return to step 4 and recheck.
7. Turn the ignition switch OFF.
8. Jump the SCS line with the HDS.
9. Disconnect PCM connectors B (44P) and C (44P).
10. Measure the resistance between PCM connector terminals C18 and C40, and between terminals C18 and B43,
Is there less than 12 Ohms?
YES - Go to step 11.
NO - Update the PCM if it does 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.
11. Disconnect the solenoid harness connector.
12. Check for continuity between PCM connector terminals C18 and C40, and between terminals C18 and B43.
Is there continuity?
YES - Repair a short to ground in the wire between PCM connector terminal C18 and the solenoid harness connector, then go to step 16.
NO - Go to step 13.
13. Inspect shift solenoid valve C.
Is shift solenoid valve C OK?
YES - Go to step 14.
NO - Replace shift solenoid valve C, then go to step 16.
14. Turn the ignition switch ON (II).
15. Measure the voltage between PCM connector terminals B2 and B43, and between terminals B2 and C40.
Is there battery voltage?
YES - Check for loose or poor connections at PCM connector terminal B2. If the connection is OK, update the PCM if it does 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. E
NO - Check for a blown No. 18 fuse in the underdash fuse/relay box. If the fuse is OK, repair an open in the wire between PCM connector terminal B2 and the under-dash fuse/relay box, then go to step 16.
16. Clear the DTC with the HDS.
17. Test-drive the vehicle for several minutes in the D position through all five gears.
18. Monitor the OBD status for P0979 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the result indicate PASSED?
YES - Troubleshooting is completed.
NO - Return to step 7 and recheck.