Rear Door Unlock Relay Circuit
Table of contents
B3809 CADILLAC Possible Causes
- Faulty Rear Door Unlock Relay
- Rear Door Unlock Relay harness is open or shorted
- Rear Door Unlock Relay circuit poor electrical connection
- Faulty Body Control Module (BCM)
How do I fix code B3809 CADILLAC?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Cost of diagnosing the B3809 CADILLAC code
The cost of diagnosing the B3809 CADILLAC code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
B3809 CADILLAC Description
The Body Control Module (BCM) internally grounds the door unlock relay control circuit for the rear door unlock relay when it receives a class 2 message from the Driver Door Module (DDM) or passenger door module (PDM). When the BCM grounds the door unlock relay control circuit the rear door unlock relay is energized and unlocks the rear doors. The Diagnostic Trouble Code (DTC) sets if the door unlock relay control circuit is shorted to ground or open for more then one second.