B12A7 Code: Meaning, Causes, and Symptoms | OBD2 Codes

B12A7 – Mode Door Actuator Slow Or Door Obstructed

 

B12A7 Possible Symptoms

 

Engine Light ON (or Service Engine Soon Warning Light)

 

B12A7 Possible Causes

 

Stuck or damaged linkage or door,Faulty Mode Door Actuator,Mode Door Actuator harness is open or shorted,Mode Door Actuator circuit poor electrical connection,Electronic Manual Temperature Control (EMTC) Module,Electronic Automatic Temperature Control (EATC) Module

 

B12A7 Description

 

Under normal operation, to rotate the mode door actuator clockwise, the Electronic Manual Temperature Control (EMTC) or Electronic Automatic Temperature Control (EATC) module supplies voltage and ground to the floor/defrost/panel mode door actuator motor through the circuit. To rotate the mode door actuator counterclockwise, the EMTC module or EATC module reverses the voltage and ground circuits. The mode door actuator feedback resistor is supplied a ground from the EMTC module or EATC module and a 5-volt reference voltage. The EMTC module or EATC module reads the voltage on the mode door actuator feedback circuit to determine the mode door actuator position by the position of the actuator feedback resistor wiper arm.