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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