B0434 GMC - Auxiliary HVAC Door Actuator Range/Performance

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What does this mean?

B0434 GMC Possible Causes

  • Faulty Auxiliary Air Temperature Actuator
  • Auxiliary Air Temperature Actuator harness is open or shorted
  • Auxiliary Air Temperature Actuator circuit poor electrical connection
  • Faulty Auxiliary Heating and Cooling Systems (HVAC) Control Module

Cost of diagnosing the B0434 GMC code

    Labor: 1.0

    The cost of diagnosing the B0434 GMC 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.

B0434 GMC Possible Symptoms

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

B0434 GMC Meaning

The Auxiliary Heating, Ventilation, and Air Conditioning (HVAC) Control Module controls the auxiliary HVAC door actuators to regulate the airflow through the auxiliary HVAC system. Each actuator consists of a stepper motor, a logic circuit, and a potentiometer. The potentiometer inside the door actuator allows the module to monitor the current position of the actuator drive shaft. The module supplies a 5-volt source voltage to the potentiometer on the 5-volt reference circuit. The module supplies ground to the potentiometer through the low reference circuit. The auxiliary HVAC control module monitors the voltage drop across the potentiometer on the door position signal circuit. When the actuator shaft rotates, the voltage on the door position signal circuit changes. The module converts the voltage value to a count value where 1 volt is approximately equal to 51 counts.

The auxiliary HVAC control module calibrates the travel range of the auxiliary HVAC door actuators when it is initially powered by the battery positive voltage circuit. During calibration, the module commands the actuators in each direction until door travel is stopped. The module stores the minimum door positions and the maximum door positions of each actuator into memory. The total travel range is calculated by subtracting the minimum door position from the maximum door position. The door actuators can be calibrated again with a scan tool.

OBDII Code B0434 GMC - Auxiliary HVAC Door Actuator Range/Performance - Engine-Codes.com

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