B129B - Driver Blend Door Actuator Drive Circuit Shorted To Battery Voltage
B129B Possible 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
How is the B129B code repair?Start by checking 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's pins.
What is the cost to diagnose the B129B code
Labor: 1.0The cost to diagnose the B129B code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
- Engine Light ON (or Service Engine Soon Warning Light)
B129B MeaningUnder 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.
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