Transmission
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 verify the A/T R SWITCH signal with the HDS in the A/T data list.
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. 10 and body ground.
Is there continuity?
YES - Go to step 6.
NO - Repair open in the wire between transmission range switch connector terminal No. 10 and ground (G101), or repair poor ground (G101), then go to step 9.
6. Turn the ignition switch ON (II).
7. Measure voltage between transmission range switch connector terminals No. 7 and No. 10.
Is there battery voltage?
YES - Go to step 8.
NO - Repair open in the wire between PCM connector terminal C21 and the transmission range switch, then go to step 9.
8. Check for continuity between transmission range switch connector terminals No. 7 and No. 10 while the shift lever is in the R position, and when the shift lever is shifted to any position other than R.
Is there continuity while the shift lever is in the R position, and no continuity when the shift lever is shifted to any position other than R?
YES - Go to step 12.
NO - Replace the transmission range switch, then go to step 9.
9. Clear the DTC with the HDS.
10. 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. Slow down and stop the wheels.
11. Monitor the OBD status for P0812 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the result indicate PASSED?
YES - Troubleshooting is complete.
NO - Check for poor connections or loose terminals at the transmission range switch and the PCM, then go to step 1.
12. Update the PCM if it does not have latest software, or substitute a known-good PCM.
13. Test-drive the vehicle in the R position at speed 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. Slow down and stop the wheels.
14. Monitor the OBD status for P0812 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the result indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM.
NO - If the PCM was updated and screen indicates FAILED, substitute a known-good PCM, then go to step 13. If the PCM was substituted, check for poor connections or loose terminals at the transmission range switch and the PCM, then go to step 1 and recheck. If the screen indicates NOT COMPLETED, go to step 13.