The P0812 trouble code indicates a problem with the reverse input circuit. Here’s what you should know:
P0812 Reverse Input Circuit
Code symptoms P0812.
1. Difficulty engaging or disengaging the reverse gear.
2. Delayed engagement when shifting into reverse.
3. Transmission slipping or hesitation when shifting into reverse.
4. Illumination of the Check Engine Light (CEL) or Malfunction Indicator Lamp (MIL) on the dashboard.
Causes of the code P0812.
1. Faulty reverse gear switch or sensor.
2. Wiring issues such as shorts, opens, or damaged wiring harness.
3. Corroded or loose electrical connections related to the reverse input circuit.
4. Malfunctioning transmission control module (TCM).
5. Mechanical problems with the transmission, such as worn-out gears or components.
Code Solutions P0812.
1. Use an OBD-II scanner to retrieve freeze frame data and any other stored trouble codes. This information can provide insight into when and how the malfunction occurred.
2. Inspect the reverse gear switch or sensor and its wiring for signs of damage, corrosion, or loose connections. Replace or repair any damaged components or wiring as needed.
3. Perform a continuity test on the reverse input circuit to check for any electrical faults. Repair any open circuits or shorts found during the test.
4. Test the reverse gear switch or sensor using a multimeter to verify its functionality. If it’s not working properly, replace it with a new one.
5. Check the transmission control module (TCM) for any fault codes related to the reverse input circuit. If necessary, perform a diagnostic scan of the TCM and address any issues found.
6. If all electrical components and wiring are in good condition and functioning properly, the problem may be mechanical. In this case, further inspection of the transmission may be necessary to identify and address any mechanical issues.