DTC Troubleshooting: P0979 (22-3)

DTC P0979:  Short in Shift Solenoid Valve C Circuit

NOTE:

1.Clear the DTC with the HDS.

2.Start the engine, and shift to the D position.

3.Check that DTC P0979 recurs.

Is DTC P0979 indicated?


YES - Go to 7.


NO - Go to 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 5.


NO - Go to 7.


5.Start the engine, and shift to the D position.

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 7.


NO - 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 4 and recheck.n

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 resistance between PCM connector terminals B20 and C40 or C44.

 

Is there less than 12 W?


YES - Go to 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.n

11.Disconnect the shift solenoid harness connector.

12.Check for continuity between PCM connector terminals B20 and C40 or C44.

 

Is there continuity?


YES - Repair short to ground in the wire between PCM connector terminal B20 and the shift solenoid harness connector, then go to 14.


NO - Go to 13.


13.Inspect shift solenoid valve C.

Is shift solenoid valve C OK?


YES - 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.n


NO - Replace shift solenoid valve C or shift solenoid harness, then go to 14.

14.Clear the DTC with the HDS.

15.Start the engine, and shift to the D position.

16.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 complete.n


NO - Return to 7 and recheck.