What the P0812 code means?
This code is triggered when the PCM (Power train Control Module) has discovered a problem with the
reverse input circuit. When the driver puts their vehicle in reverse, they do so by using the shifter, which is
then energized. The PCM monitors this process to ensure the voltage from this switch falls within an
acceptable range predetermined by the manufacturer.
What causes the P0812 code?
Faulty Reverse Input Switch
Reverse Input Switch harness is open or shorted
Reverse Input Switch circuit poor electrical connection
What are the symptoms of the P0812 code?
Symptoms may include failure of the back-up lamps to illuminate, a stored code, and possibly an
illuminated service engine soon lamp.
Common mistakes when diagnosing the P0812 code:
Technicians report that the back-up lamp bulbs are frequently condemned in error when the reverse input
switch, wiring, or connectors are at fault.
How serious is the P0812 code?
There is nothing inherently dangerous about the P0812 code. That being said, if it results in the backup
lamps burning out, the driver will need to get around with them. That can be dangerous as other drivers
won't have forewarning when the automobile is backing up. Getting caught with this problem could earn the
owner a ticket, too, one that will probably cost a lot more than just going in for repairs.
What repairs can fix the P0812 code?
Replacing the reverse input switch
Repairing or replacing faulty or corroded connectors or wiring.