B12B8 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 do I fix code B12B8
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's pins.
Cost of diagnosing the B12B8 code
Labor: 1.0The cost of diagnosing the B12B8 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.
B12B8 Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
B12B8 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.
B12B8 More InformationNeed more information on how to fix the B12B8 code?
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