Engine-Codes - Generic - B129B

B129B Code - Driver Blend Door Actuator Drive Circuit Shorted To Battery Voltage

- Code Popularity: 1,244 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
Table of contents
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What are the Possible Causes of the DTC B129B?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Stuck or damaged linkage or door
  • Faulty Blend Door Actuator
  • Blend Door Actuator harness is open or shorted
  • Blend Door Actuator circuit poor electrical connection
  • Electronic Manual Temperature Control (EMTC) Module
  • Electronic Automatic Temperature Control (EATC) Module
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How to Fix the DTC B129B?

Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

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What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the B129B code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

What Does the B129B Code Mean?

Under normal operation, to rotate the blend door actuator clockwise, the Electronic Manual Temperature Control (EMTC) Module or Electronic Automatic Temperature Control (EATC) Module supplies voltage to the blend door actuator motors through the door actuator feed A circuits and supplies ground through the door actuator feed B circuits. To rotate the blend door actuator counterclockwise, the EMTC module or EATC module reverses the voltage and ground circuits.
The blend door actuator feedback resistors are supplied a ground from the EMTC module or EATC module by the blend door actuator return circuits and a 5-volt reference voltage on the blend door actuator reference circuits. The EMTC module or EATC module reads the voltage on the blend door actuator feedback circuits to determine the blend door actuator position by the position of the actuator feedback resistor wiper arm.

B129B Code - Driver Blend Door Actuator Drive Circuit Shorted To Battery Voltage

Need more Information on the Code?

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Code B129B Information for Specific Makes

  • B129B Ford Driver Blend Door Actuator Drive Circuit Shorted To Battery Voltage
  • B129B Lincoln Driver Blend Door Actuator Drive Circuit Shorted To Battery Voltage
  • B129B Mercury Driver Blend Door Actuator Drive Circuit Shorted To Battery Voltage

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