DTC Troubleshooting
DTC P0816: Short in Transmission Gear Selection Switch Downshift Switch Circuit, or Transmission Gear Selection Switch Downshift Switch Stuck ONNOTE:
- Before you troubleshoot, record all freeze data and any on-board snapshot, and review General Troubleshooting Information.
- This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.
1. Turn the ignition switch ON (II).
2. Shift to the P position.
3. Verify the transmission gear selection switch downshift switch signal input with the HDS in the A/T data list.
Is DOWNSHIFT SW ON?
YES - Go to step 4.
NO - Intermittent failure, the system is OK at this time. Check the S-DN (GRN) wire for an intermittent short to ground between the transmission gear selection switch and PCM.
4. Turn the ignition switch OFF.
5. Disconnect the transmission gear selection switch/park pin switch/A/T gear position indicator panel light connector.
6. Turn the ignition switch ON (II).
7. Verify the transmission gear selection switch downshift switch signal input with the HDS in the A/T data list.
Is DOWNSHIFT SW ON?
YES - Go to step 8.
NO - Replace the transmission gear selection switch, then go to step 12.
8. Turn the ignition switch OFF.
9. Jump the SCS line with the HDS.
10. Disconnect PCM connector E (31P).
11. Check for continuity between transmission gear selection switch connector terminal No. 8 and body ground.
Is there continuity?
YES - Repair a short to body ground in the wire between PCM connector terminal E13 and the transmission gear selection switch, then go to step 12.
NO - Go to step 20.
12. Reconnect all connectors.
13. Turn the ignition switch ON (II).
14. Clear the DTC with the HDS.
15. Start the engine in the P position, wait for more than 10 seconds, then shift position to the M position.
16. Push the shift lever toward the upshift position (+) slowly, and release it; repeat this test 10 times or more.
17. Pull the shift lever toward the downshift position (-) slowly, and release it; repeat this test 10 times or more.
18. Check for Temporary DTCs or DTCs with the HDS. Is DTC P0816 indicated?
YES - Check for poor connections or loose terminals at the transmission gear selection switch and the PCM, then go to step 1.
NO - Go to step 19.
19. Monitor the OBD STATUS for P0816 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete.
NO - Return to step 1 and recheck.
20. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
21. Start the engine in the P position, wait for more than 10 seconds, then shift position to the M position.
22. Push the shift lever toward the upshift position (+) slowly, and release it; repeat this test 10 times or more.
23. Pull the shift lever toward the downshift position (-) slowly, and release it; repeat this test 10 times or more.
24. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0816 indicated?
YES - Check for poor connections or loose terminals at the transmission gear selection switch and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 21. If the PCM was substituted, go to step 1.
NO - Go to step 25.
25. Monitor the OBD STATUS for P0816 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete.
NO - Return to step 1 and recheck.