Description And Operation: Operation

All climate control communications take place on the Controller Area Network - Interior High Speed (CAN IHS) bus. HVAC control logic takes place in the HVAC module. All front and rear HVAC control logic is contained in the front HVAC module.

The purpose of the rear HVACR module is to follow CAN IHS commands from the front HVAC module and position the rear HVAC doors and control the rear blower speed only.

It also reads the rear HVAC air outlet temperature sensor and sends that value to the front HVAC module over CAN IHS.

Front HVAC Module 

The front HVAC module is responsible for controlling the following MTC/ATC Systems:

• Air distribution modes (actuators)
• Blower motor speed
• Air recirculation/vent modes

The front HVAC module receives input from the following sensors:

• Evaporator temperature sensor
• Sun load sensor
• Cabin temperature sensor
• Humidity sensor

If equipped with Tri-Zone ATC:

• Left floor temperature sensor
• Right floor temperature sensor
• Left panel temperature sensor
• Right panel temperature sensor

Rear HVAC Module 

The HVACR module is responsible for controlling the following MTC/ATC Systems:

• Air distribution mode (actuator)
• Blower motor speed
• Air recirculation/vent modes

The HVACR module receives input from the following sensors (if equipped with Tri-Zone):

• Rear floor temperature sensor
• Rear panel temperature sensor