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 , 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 , 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 . 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 , and check the OBD STATUS again.
-NOT COMPLETED- Meet the test condition, and check the OBD STATUS again.