DTC P0812: Transmission Range Switch ATP R Switch

WARNING: This page is about a different car, the 2013 Honda Odyssey, 2012 Honda Odyssey, and 2011 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review General Troubleshooting Information (see GENERAL TROUBLESHOOTING INFORMATION ).
This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.

Turn the ignition switch to ON (II).
Shift to R, and monitor 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.
Turn the ignition switch to LOCK (0).
Disconnect the transmission range switch connector.
Connect a jumper wire between transmission range switch connector terminal No. 8 to body ground.

Fig 1: Connecting Jumper Wire Between Transmission Range Switch Connector Terminal No. 8 To Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to ON (II).
Check the transmission range switch signal is ON with the HDS in the A/T Data List.
Is the transmission range switch signal ON?

YES -Replace the transmission range switch (see TRANSMISSION RANGE SWITCH REPLACEMENT ), then go to step 8.

NO -Repair an open in the wire between the transmission range switch and PCM connector terminal C25, then go to step 8. If circuit checks OK, go to step 15.
Reconnect all connectors.
Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. With the brake pedal pressed, then shift to R, and wait for at least 2 seconds.
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.
Check for Pending or Confirmed 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 14.
Monitor the OBD status for P0812 in the DTCs MENU with the HDS.
Does the HDS indicate PASSED?

YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 13, go to the INDICATED DTC'S TROUBLESHOOTING .

NO -If the HDS indicates FAILED, check for poor connections or loose terminals between the transmission range switch and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, go to step 11.
Reconnect all connectors.
Update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ).
Start the engine. With the brake pedal pressed, then shift to R, and wait for at least 2 seconds.
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.
Check for Pending or Confirmed 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 (see SUBSTITUTING THE PCM ), then go to step 17. If the PCM was substituted, go to step 1.

NO -Go to step 20.
Monitor the OBD status for P0812 in the DTCs MENU with the HDS.
Does the HDS indicate PASSED?

YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see PCM REPLACEMENT ). If any other Pending or Confirmed DTCs were indicated in step 19, go to the INDICATED DTC'S TROUBLESHOOTING .

NO -If the HDS 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 (see SUBSTITUTING THE PCM ), then go to step 17. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, go to step 17.