B1812 Code: Meaning, Causes, and Symptoms | OBD2 Codes

B1812 – Lamp Backup Switch Input Circuit Short To Battery

 

B1812 Possible Symptoms

 

Engine Light ON (or Service Engine Soon Warning Light)

 

B1812 Possible Causes

 

Faulty Lamp Backup Switch,Lamp Backup Switch harness is open or shorted,Lamp Backup Switch circuit poor electrical connection,Faulty Body Control Module (BCM)

 

B1812 Description

 

The Body Control Module (BCM) monitors the Lamp Backup Switch. The BCM sets the OBDII code when the Lamp Backup Switch is not to factory specifications.