OBDII Code List

B0408 CHEVROLET - Front Temperature Control Circuit

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

B0408 Chevrolet Possible Causes

  • Faulty Air Temperature Actuator
  • Air Temperature Actuator harness is open or shorted
  • Air Temperature Actuator circuit poor electrical connection
  • Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module

B0408 Chevrolet Possible Symptoms

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

B0408 Chevrolet Meaning

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.
OBDII Code B0408 Chevrolet - Front Temperature Control Circuit - Engine-Codes.com

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