DTC Troubleshooting

DTC Troubleshooting: P0979 (22-3)

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 How to Troubleshoot the A/T System.
- 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.

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.

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.

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 Shift Solenoid Valve C Test and Replacement.

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

19. 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.

NO -

Replace the PCM Service and Repair.