OBD Guide
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B12BE

Heated Backlight/Mirror Relay Drive Circuit Shorted To Battery Voltage

B12BE is an OBD-II diagnostic trouble code meaning: Heated Backlight/Mirror Relay Drive Circuit Shorted To Battery Voltage. Common causes: short circuit in wiring harness, faulty heating relay. Estimated repair cost: $33–111.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$33–111 (est.)

Symptoms

  • Heated rear window does not work
  • Heated mirrors don't work
  • Check Engine Light Is On
  • Heating turns on spontaneously

Causes

  • Short circuit in wiring harness
  • Faulty heating relay
  • Damage to the control circuit in the module
  • Contact corrosion
  • Mechanical damage to wiring

How to Fix

  1. Check the integrity of the wiring harness to the heating relay
  2. Test the heating relay for a short circuit
  3. Check the voltage on the relay control wire
  4. Inspect connectors and contacts for corrosion
  5. If necessary, replace relays or damaged wires

Related codes

B12BDB12BFB12C0

FAQ

What does the B12BE code mean?

B12BE is an OBD-II diagnostic trouble code that indicates: Heated Backlight/Mirror Relay Drive Circuit Shorted To Battery Voltage

What causes a B12BE error code?

The most common causes of B12BE include: Short circuit in wiring harness; Faulty heating relay; Damage to the control circuit in the module; Contact corrosion.

How do I fix a B12BE diagnostic trouble code?

To fix B12BE: Check the integrity of the wiring harness to the heating relay. Test the heating relay for a short circuit. Check the voltage on the relay control wire. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B12BE?

Limited driving only, diagnose soon

How much does it cost to fix B12BE?

The estimated repair cost for B12BE is $33–111. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat