OBD Guide
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B12B3

Blend Door Actuator Drive Circuit Shorted To Battery Voltage

B12B3 is an OBD-II diagnostic trouble code meaning: Blend Door Actuator Drive Circuit Shorted To Battery Voltage. Common causes: short circuit in wiring harness, damper motor malfunction. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Incorrect operation of climate control
  • No air temperature adjustment
  • The damper does not respond to commands
  • Possible extraneous noise due to jamming of the drive

Causes

  • Short circuit in wiring harness
  • Damper motor malfunction
  • Problems in the climate control control unit
  • Mechanical jamming of the damper

How to Fix

  1. Check the wiring harness for damage and short circuits.
  2. Check the resistance and voltage at the damper actuator
  3. Replace the damper actuator if necessary
  4. Check the operation of the climate control control unit

Related codes

B12B4B12B5

FAQ

What does the B12B3 code mean?

B12B3 is an OBD-II diagnostic trouble code that indicates: Blend Door Actuator Drive Circuit Shorted To Battery Voltage

What causes a B12B3 error code?

The most common causes of B12B3 include: Short circuit in wiring harness; Damper motor malfunction; Problems in the climate control control unit; Mechanical jamming of the damper.

How do I fix a B12B3 diagnostic trouble code?

To fix B12B3: Check the wiring harness for damage and short circuits.. Check the resistance and voltage at the damper actuator. Replace the damper actuator if necessary. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B12B3?

Limited driving only, diagnose soon

How much does it cost to fix B12B3?

The estimated repair cost for B12B3 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat