DTC Troubleshooting
DTC P0812: Open in Transmission Range Switch ATP R Switch CircuitNOTE:
^ 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 R position, and check the A/T R SWITCH in the DATA LIST with the HDS.
Is the A/T R SWITCH ON?
YES - Intermittent failure, the system is OK at this time.
NO - Go to step 3.
3. Turn the ignition switch OFF.
4. Disconnect the transmission range switch connector.
5. Check for continuity between transmission range switch connector terminal No. 5 and body ground.
Is there continuity?
YES - Go to step 6.
NO - Repair an open in the wire between the transmission range switch and ground (G101), or repair a poor ground (G101), then go to step 10.
6. Turn the ignition switch ON (II).
7. Measure the voltage between transmission range switch connector terminals No. 3 and No. 5.
Is there voltage?
YES - Go to step 8.
NO - Go to step 9.
8. Check for continuity between the No. 3 and No. 5 terminals at the transmission range switch.
Is there continuity when the shift lever is in the R position, and no continuity when the shift lever is in any position other than R?
YES - Go to step 16.
NO - Replace the transmission range switch, then go to step 10.
9. Measure the voltage between PCM connector terminal D16 and body ground.
Is there battery voltage?
YES - Repair open in the wire between the transmission range switch and PCM connector terminal D16, then go to step 10.
NO - Go to step 16.
10. Reconnect all connectors.
11. Turn the ignition switch ON (II).
12. Clear the DTC with the HDS.
13. Test-drive the vehicle in the R position at speeds below 3 mph (5 km/h) for more than 2 seconds, then increase the speed and test-drive at speeds over 3 mph (5 km/h) for more than 2 seconds.
14. Check for DTCs with the HDS.
Is DTC P0812 indicated?
YES - Check for poor connections or loose terminals between the transmission range switch and the PCM, then go to step 1.
NO - Go to step 15.
15. Monitor the OBD STATUS for P0812 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other DTCs were indicated in step 14, go to the indicated DTC's troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals between the transmission range switch and the PCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 13.
16. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
17. Test-drive the vehicle in the R position at speeds below 3 mph (5 km/h) for more than 2 seconds, then increase the speed and test-drive at speeds over 3 mph (5 km/h) for more than 2 seconds.
18. Check for DTCs with the HDS.
Is DTC P0812 indicated?
YES - Check for poor connections or loose terminals between the transmission range switch and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 17. If the PCM was substituted, go to step 1.
NO - Go to step 19.
19. Monitor the OBD STATUS for P0812 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other DTCs were indicated in step 18, go to the indicated DTC's troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals between the transmission range switch and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 17. If the PCM was substituted, go to, step 1. If the screen, indicates NOT COMPLETED, go to step 17.