DTC P0979: Shift Solenoid Valve C (Short)
- Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review General Troubleshooting Information (see GENERAL TROUBLESHOOTING INFORMATION ).
- This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.
- Some wire colors vary according to the model year, and are indicated with an asterisk as follows:
- *(1): '09 - 10 models
- *(2): '11 - 12 models
- Clear the DTC with the HDS.
- Start the engine, and test-drive the vehicle:
- Seven-position transmission: Drive the vehicle in D3, and let the transmission shift through all three gears. Drive the vehicle in 3rd gear for at least 1 second, then slow down to a stop.
- Five-position transmission: Drive the vehicle in 1st thru 3rd gears in the sequential sportshift mode in S. Drive the vehicle in 3rd gear for at least 1 second, then slow down to a stop.
- Check that DTC P0979 recurs.
Is DTC P0979 indicated?
YES - go to step 7.
NO -Go to step 4.
- Select Shift Solenoid C in the Miscellaneous Test Menu, and test shift solenoid valve C with the HDS.
Is a clicking sound heard?
YES -Go to step 5.
NO - go to step 7.
- Start the engine, and test-drive the vehicle:
- Seven-position transmission: Drive the vehicle in D3, and let the transmission shift through all three gears, then slow down to a stop. Shift into P, and wait for at least 1 second.
- Five-position transmission: Drive the vehicle in 1st thru 3rd gears in the sequential sportshift mode in S, then slow down to a stop. Shift into P, and wait for at least 1 second.
- Monitor the OBD status for P0979 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the HDS indicate FAILED?
YES -Go to step 7.
NO -Intermittent failure, the system is OK at this time. Check the SHC wire for an intermittent short to ground between shift solenoid valve C and the PCM. If the HDS indicates NOT COMPLETED, return to step 4 and recheck.
- Turn the ignition switch to LOCK (0).
- Jump the SCS line with the HDS.
- Disconnect PCM connector B (49P).
- Measure the resistance between PCM connector terminal B21 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there less than 12 Ω?
YES -Go to step 11.
NO - go to step 17.
- Disconnect the shift solenoid harness connector.
- Check for continuity between PCM connector terminal B21 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair a short in the wire between PCM connector terminal B21 and the shift solenoid harness connector, then go to step 22.
NO -Go to step 13.
- Inspect shift solenoid valve C (see
SHIFT SOLENOID VALVE TEST ).
Is shift solenoid valve C OK?
YES -Go to step 14.
NO -Replace shift solenoid valve C or the shift solenoid harness (see SHIFT SOLENOID VALVE AND SHIFT SOLENOID WIRE HARNESS REPLACEMENT ), then go to step 22.
- Disconnect PCM connector A (49P).
- Turn the ignition switch to ON (II).
- Measure the voltage between PCM connector terminal A1 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -Go to step 17.
NO -Check for a blown No. 7 (10 A) fuse in the under-hood fuse/relay box. If the fuse is OK, repair an open or a short in the wire between PCM connector terminal A1 and the under-hood fuse/relay box, then go to step 22.
- Connect PCM connectors.
- Update the A/T software in the PCM if it does not have the latest software (see ECM/PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE ECM/PCM ).
- Start the engine, and test-drive the vehicle:
- Seven-position transmission: Drive the vehicle in D3, and let the transmission shift through all three gears, then slow down to a stop. Shift into P, and wait for at least 1 second.
- Five-position transmission: Drive the vehicle in 1st thru 3rd gears in the sequential sportshift mode in S, then slow down to a stop. Shift into P, and wait for at least 1 second.
- Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0979 indicated?
YES -If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the PCM was substituted, go to step 1.
NO -Go to step 21.
- Monitor the OBD status for P0979 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the HDS indicate PASSED?
YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see ECM/PCM REPLACEMENT ). If any other DTCs were indicated on step 20, go to the indicated DTC's troubleshooting.
NO -Check for an intermittent short in the wire between shift solenoid valve C and the PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, return to step 19 and recheck.
- Reconnect all connectors.
- Clear the DTC with the HDS.
- Start the engine, and test-drive the vehicle:
- Seven-position transmission: Drive the vehicle in D3, and let the transmission shift through all three gears, then slow down to a stop. Shift into P, and wait for at least 1 second.
- Five-position transmission: Drive the vehicle in 1st thru 3rd gears in the sequential sportshift mode in S, then slow down to a stop. Shift into P, and wait for at least 1 second.
- Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0979 indicated?
YES -Check for an intermittent short in the wire between shift solenoid valve C and the PCM, then go to step 1.
NO -Go to step 26.
- Monitor the OBD status for P0979 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the HDS indicate PASSED?
YES -Troubleshooting is complete. If any other DTCs were indicated on step 25, go to the indicated DTC's troubleshooting.
NO -Check for an intermittent short in the wire between shift solenoid valve C and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, return to step 24 and recheck.