C2806 Code: Meaning, Causes, and Symptoms | OBD2 Codes
C2806 – Trailer Brake Output Circuit Short To VBattery
C2806 Possible Symptoms
Anti-Lock Brake System (ABS) Warning Light ON,Engine Light ON (or Service Engine Soon Warning Light)
C2806 Possible Causes
Faulty Trailer Brake Control (TBC) Module,Trailer Brake Control (TBC) Module harness is open or shorted,Trailer Brake Control (TBC) Module circuit poor electrical connection
The braking energy that is provided to the trailer is varied with a Pulse Width Modulated (PWM) signal along the circuit that switches between 0 volt and battery voltage, the higher the duty cycle the more braking power available. The Trailer Brake Control (TBC) Module varies the PWM signal based on various inputs such as the brake pressure transducer, TBC module manual slider switch and the TBC module gain buttons. With the vehicle stationary and with the manual slider switch fully to the left with a gain of 10, there should be greater than 10-12 volts supplied to pin 3 of the 7-pin trailer tow connector. Every 4 seconds the TBC module sends a voltage pulse along circuit CAT19 (BU) to pin 3 of the 7-pin trailer tow connector to determine whether or not a trailer is connected.