B023A BUICK - HVAC Actuators Supply Voltage
Repair Importance Level:
Repair Difficulty Level:
Possible causes
- Faulty Heating, Ventilation, and Air Conditioning (HVAC) Actuators
- HVAC Actuators harness is open or shorted
- HVAC Actuators circuit poor electrical connection
- Faulty HVAC Control Module
Possible symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
B023a Buick Description
Stepper motors are used for temperature regulation, air distribution control and recirculation door control. With the switches and dials on the Heating, Ventilation, and Air Conditioning (HVAC) controls, air temperature door position, mode door position and recirculation door position can be selected. The selected values are passed to the HVAC Control Module via serial data. The HVAC control module supplies a 12 V reference voltage to the stepper motors and energizes the 4 stepper motor coils with a pulsed ground signal. The stepper motors move the appropriate doors into the calculated positions, in order to reach the desired positions.