Left Rear Window Relay Power Circuit
Table of contents
B3821 GMC Possible Causes
- Faulty Body Control Module (BCM)
- Body Control Module (BCM) harness is open or shorted
- Body Control Module (BCM) circuit poor electrical connection
How do I fix code B3821 GMC?
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 B3821 GMC code
The cost of diagnosing the B3821 GMC 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)
B3821 GMC Description
Battery positive voltage is supplied to the left rear power window switch and the up and down relays through the window lockout signal circuit. If the window lockout function is disabled, the Body Control Module (BCM) supplies battery positive voltage to the switch and relays and the left rear window operates normally. If the window lockout function is enabled, the BCM will not supply battery positive voltage to the switch and relays and the left rear window will be inoperative unless it is operated from the driver power window switch. The Diagnostic Trouble Code (DTC) sets when the window lockout function is disabled and the window lockout signal circuit is shorted to ground.