P0979

DTC P0979: Short in Shift Solenoid Valve Circuit

NOTE:
^ 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. Start the engine in the P position.
3. Check that DTC P0979 recurs.
Is DTC P0979 indicated?
YES - Go to step 7.
NO - Go to step 4.
4. Select SHIFT SOL TEST in MISC. TEST MENU, then carry out A/T SHIFT SOL C test in SHIFT SOL TEST MENU with the HDS.
5. Start the engine, and shift to the D5 position.
6. Check the OBD STATUS in DTCs MENU for a pass/fail test for code P0979.
Did the result indicate a fail?
YES - Go to step 7.
NO - Intermittent failure, the system is OK at this time. If the tester indicates NOT COMPLETE, return to step 4 and recheck.
7. Turn the ignition switch OFF.
8. Jump the SCS line with HDS.
9. Disconnect PCM connector A (73P).





10. Measure the resistance between PCM connector terminals A13 and A39 or A40.
Is there less than 12 ohms ?
YES - Go to step 11.
NO - Go to step 14.
11. Disconnect the solenoid harness connector at the transmission housing.





12. Check the continuity between PCM connector terminals A13 and A39 or A40.
Is there continuity ?
YES - Repair short to ground in the wire between PCM connector terminal A13 and 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 A19 and A39 or A40.
Is there battery voltage?
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.
NO - Check for blown No. 6 fuse in the driver's under-dash fuse/relay box. If the fuse is OK, repair open or short in the wire between PCM connector terminal A19 and the driver's under-dash fuse/relay box, then go to step 16.
16. Clear the DTC with the HDS.
17. Start the engine, and shift to the D5 position.
18. Check the OBD STATUS in DTCs MENU for a pass/fail test of code P0979.
Did the result indicate a pass?
YES - The problem has been corrected.
NO - Return to step 1 and recheck.