OBD Guide
ENFRDEESPT

B12BF

Heated Backlight/Mirror Relay Drive Circuit Open Or Shorted To Ground

B12BF is an OBD-II diagnostic trouble code meaning: Heated Backlight/Mirror Relay Drive Circuit Open Or Shorted To Ground. Common causes: faulty heating relay, broken or damaged wiring harness. Estimated repair cost: $22–111.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$22–111 (est.)

Symptoms

  • Heated rear window does not work
  • Heated mirrors don't work
  • Malfunction indicator on the instrument panel

Causes

  • Faulty heating relay
  • Broken or damaged wiring harness
  • Contact corrosion
  • Short to ground
  • Problems with the body module

How to Fix

  1. Check the heating circuit fuse
  2. Check the heating relay for malfunctions
  3. Inspect the wiring harness for damage
  4. Check contacts for corrosion
  5. If necessary, replace the relay or repair the wiring harness

Related codes

B12C0B12C1

FAQ

What does the B12BF code mean?

B12BF is an OBD-II diagnostic trouble code that indicates: Heated Backlight/Mirror Relay Drive Circuit Open Or Shorted To Ground

What causes a B12BF error code?

The most common causes of B12BF include: Faulty heating relay; Broken or damaged wiring harness; Contact corrosion; Short to ground.

How do I fix a B12BF diagnostic trouble code?

To fix B12BF: Check the heating circuit fuse. Check the heating relay for malfunctions. Inspect the wiring harness for damage. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B12BF?

Yes, but get it checked soon

How much does it cost to fix B12BF?

The estimated repair cost for B12BF is $22–111. Actual cost depends on your vehicle, location, and labor rates.

FRDEESPT

See also: Russian version · NationStat