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 to ON (II).
2. Shift the shift lever into R, 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 to LOCK (0).
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 open in the wire between the transmission range switch and ground (G101, G102), or repair poor ground (G101, G102), then go to step 15.
6. Turn the ignition switch to 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 - Repair open in the wire between the transmission range switch and PCM connector terminal D16, then go to step 15.
8. Check for continuity between connector terminals No. 3 and No. 5 at the transmission range switch.
Is there continuity when the shift lever is in R, and no continuity when the shift lever is shifted to any position other than R?
YES - Check for poor connections and loose terminals at the transmission range switch and the PCM. If the connections are OK, go to step 9.
NO - Replace the transmission range switch, then go to step 15.
9. Connect the transmission range switch connector.
10. Update the A/T software in the PCM if it does not have the latest software, or substitute a known-good PCM.
11. Test-drive the vehicle in R at speeds below 3 mph (5 km/h) for at least 2 seconds, then increase the speed and test-drive at speeds over 3 mph (5 km/h) for at least 2 seconds. Slow down and stop the wheels.
12. Turn the ignition switch to LOCK (0). Repeat step 11, then go to step 13.
13. Check for DTC(s) in the DTCs/Freeze Data in A/T Mode Menu with the HDS.
Is DTC P0812 indicated?
YES - If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to step 1.
NO - Go to step 14.
14. Monitor the OBD STATUS for P0812 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. If any other DTCs were indicated on step 13, go to the indicated DTC's troubleshooting.
NO - Check for poor connections and loose terminals at the transmission range switch and the PCM. If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, return to step 11 and recheck.
15. Clear the DTC with the HDS.
16. Test-drive the vehicle in Rat speeds below 3 mph (5 km/h) for at least 2 seconds, then increase the speed and test-drive at speeds over 3 mph (5 km/h) for at least 2 seconds. Slow down and stop the wheels.
17. Turn the ignition switch to LOCK (0). Repeat step 16, then go to step 18.
18. Check for DTC(s) in the DTCs/Freeze Data in A/T Mode Menu with the HDS.
Is DTC P0812 indicated?
YES - Check for poor connections and loose terminals at the transmission range switch and the PCM, then go to step 1.
NO - Go to step 19.
19. Monitor the OBD STATUS for P0812 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 18, go to the indicated DTC's troubleshooting.
NO - Check for poor connections and loose terminals at the transmission range switch and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, return to step 16 and recheck.