B0409 CHEVROLET - Temperature Control 1 Circuit Range
Repair Importance Level:
Repair Difficulty Level:
Possible causes
- Faulty Left Air Temperature Actuator
- Left Air Temperature Actuator harness is open or shorted
- Left Air Temperature Actuator circuit poor electrical connection
- Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module
Possible symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
B0409 Chevrolet Description
Stepper motors are used for temperature regulation, air distribution control and recirculation door control. With the switches and dials on the HVAC controls, air temperature door position, mode door position and recirculation door position can be selected. The selected values are passed to the Heating, Ventilation, and Air Conditioning (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.