DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P0812

DTC P0812 : Transmission Range Switch ATP R Switch

NOTE:
* Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review the General Troubleshooting Information How To Troubleshoot The A/T System.
* This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.

1. A/T R Switch signal check:

A/T R Switch signal check
-1. Turn the ignition switch to ON (II).

-2. Shift to R, and check the A/T R Switch with the HDS in the A/T Data List.

Is the A/T R Switch ON?
-YES- The A/T R Switch signal is OK. Intermittent failure, the system is OK at this time.
-NO- Go to step 2.

2. Transmission range switch check:

Transmission range switch check
-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connector.





-3. Connect terminals A and B with a jumper wire.









-4. Turn the ignition switch to ON (II).

-5. Check the A/T R Switch signal with the HDS.

Is the A/T R Switch ON?
-YES- Replace the transmission range switch Service and Repair, then do the repair verification.
-NO- Transmission range switch is OK. Go to step 3.

3. Open wire check (ATP_R line):

Open wire check (ATP_R line)
-1. Turn the ignition switch to LOCK (0).

-2. Jump the SCS line with the HDS.

-3. Disconnect the following connector.





-4. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- The ATP_R wire is OK. Update the PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good PCM Service and Repair, then do the repair verification.
-NO- Repair an open in the ATP_R wire between the transmission range switch and the PCM, then do the repair verification.

Repair verification (OBD STATUS check):

-1. Reconnect all connectors.

-2. Turn the ignition switch to ON (II).

-3. Clear the DTC with to the HDS.

-4. Test-drive the vehicle with the shift lever in R at speeds below 3 mph (5 km/h) for at least 2 seconds. Then increase the speed and drive over 3 mph (5 km/h) for at least 2 seconds.

-5. Monitor the OBD STATUS for P0812 in the DTCs MENU with the HDS.

Does the HDS indicate PASSED, FAILED, or NOT COMPLETED?
-PASSED- Troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair. Check for other DTC after this troubleshooting. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.
-FAILED- Go to step 1 and recheck. If the PCM was updated, substitute a known-good PCM Service and Repair, and check the OBD STATUS again.
-NOT COMPLETED- Meet the test condition, and check the OBD STATUS again.