OBD Guide
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B129B

Driver Blend Door Actuator Drive Circuit Shorted To Battery Voltage

B129B is an OBD-II diagnostic trouble code meaning: Driver Blend Door Actuator Drive Circuit Shorted To Battery Voltage. Common causes: short circuit in drive circuit wiring, mixer damper drive 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 (temperature is not regulated)
  • Lack of air supply at a certain temperature
  • Noises from the damper area when trying to adjust

Causes

  • Short circuit in drive circuit wiring
  • Mixer damper drive malfunction
  • Problems in the climate control control unit
  • Mechanical jamming of the damper

How to Fix

  1. Check the integrity of the wiring and connectors of the drive circuit
  2. Test the mixer damper drive
  3. Check the operation of the climate control control unit
  4. If necessary, replace the drive or repair the wiring

Related codes

B129AB129CB129D

FAQ

What does the B129B code mean?

B129B is an OBD-II diagnostic trouble code that indicates: Driver Blend Door Actuator Drive Circuit Shorted To Battery Voltage

What causes a B129B error code?

The most common causes of B129B include: Short circuit in drive circuit wiring; Mixer damper drive malfunction; Problems in the climate control control unit; Mechanical jamming of the damper.

How do I fix a B129B diagnostic trouble code?

To fix B129B: Check the integrity of the wiring and connectors of the drive circuit. Test the mixer damper drive. Check the operation of the climate control control unit. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B129B?

Limited driving only, diagnose soon

How much does it cost to fix B129B?

The estimated repair cost for B129B is $56–167. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat