DTC Troubleshooting

DTC P0979:


Short in Shift Solenoid Valve C Circuit




NOTE:



Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review the General Troubleshooting Information.



This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.



If DTC P0979 is stored in the PCM, the transmission does not shift to 2nd or 5th gear because of the fail-safe function.



1. Turn the ignition switch to ON (II).



2. Clear the DTC with the HDS.



3. Start the engine in P, and wait for at least 1 second.



4. Check for Pending or Confirmed DTCs with the HDS.



Is DTC P0979 indicated?



YES -
Go to step 5.



NO -
Intermittent failure, the system is OK at this time.

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5. Turn the ignition switch to LOCK (0).



6. Check for a blown No. 20 (15 A) fuse in the driver's under-dash fuse/relay box.



Is the No. 20 (15 A) fuse OK?



YES -
Go to step 7.



NO -
Repair a short to body ground in the wire between PCM connector terminal A1 and the driver's under-dash fuse/relay box.

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7. Jump the SCS line with the HDS.



8. Disconnect PCM connectors A (49P).



9. Turn the ignition switch to ON (II).



10. Measure the voltage between PCM connector terminals A1 and body ground.





Is there battery voltage?



YES -
Go to step 11.



NO -
Repair an open in the wire between PCM connector terminal A1 and the driver's under-dash fuse/relay box.

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11. Turn the ignition switch to LOCK (0).



12. Connect PCM connector A (49P).



13. Disconnect the shift solenoid valve C connector.



14. Turn the ignition switch to ON (II).



15. Clear the DTC with the HDS.



16. Start the engine in P, and wait for at least 1 second.



17. Check for Pending or Confirmed DTCs with the HDS.



Is DTC P0979 indicated?



YES -
Go to step 18.



NO -
Replace shift solenoid valve C.

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8. Turn the ignition switch to LOCK (0).



9. Jump the SCS line with the HDS.



20. Disconnect PCM connector C (49P).



21. Check for continuity between PCM connector terminals C9 and body ground.






Is there continuity?



YES -
Repair a short to body ground in the wire between PCM connector terminal C9 and shift solenoid valve C connector terminal No. 2.

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NO -
Replace the PCM.

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