B3821
Left Rear Window Relay Power Circuit
B3821 is an OBD-II diagnostic trouble code meaning: Left Rear Window Relay Power Circuit. Common causes: open or short circuit in wiring harness, power window relay malfunction. Estimated repair cost: $22–111.
Symptoms
- Rear left window does not work
- No response to control button
- Relay clicks without glass movement
Causes
- Open or short circuit in wiring harness
- Power window relay malfunction
- Fuse problems
- Defective window lift motor
How to Fix
- Check the condition of the circuit fuse
- Inspect the wiring harness for damage
- Check the operation of the power window relay
- If necessary, replace the relay or motor
Related codes
Error B3821 by Vehicle Brand
FAQ
What does the B3821 code mean?
B3821 is an OBD-II diagnostic trouble code that indicates: Left Rear Window Relay Power Circuit
What causes a B3821 error code?
The most common causes of B3821 include: Open or short circuit in wiring harness; Power window relay malfunction; Fuse problems; Defective window lift motor.
How do I fix a B3821 diagnostic trouble code?
To fix B3821: Check the condition of the circuit fuse. Inspect the wiring harness for damage. Check the operation of the power window relay. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with B3821?
Limited driving only, diagnose soon
How much does it cost to fix B3821?
The estimated repair cost for B3821 is $22–111. Actual cost depends on your vehicle, location, and labor rates.
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