Heating Ventilation And Air Conditioning Module

WARNING: This page is about a different car, the 2021 Jeep Grand Cherokee L. However, it is still accessible from the selected car via links, so may be relevant.

DESCRIPTION

Courtesy of CHRYSLER GROUP, LLC

The Heating, Ventilation and Air Conditioning (HVAC) module (1) is a microcontroller designed to operate the heating and A/C system, using the Controller Area Network - Interior High Speed (CAN-IHS) data bus. The HVAC module has a plastic housing with two electrical connector receptacles, two mounting screw bosses and two locating tabs. The 36-pin electrical connector contains the power circuits, CAN-IHS circuits that connect the HVAC module to the other modules in the vehicle as well as circuits for the controls on the HVAC housing and the A/C heater control. The 8-pin connector contains the in-car temperature sensor signal circuits.

The HVAC module receives broadcast messages from the Body Control Module (BCM) containing the ambient temperature sensor data and the Humidity Rain Light Sensor Module (HRLSM) data.

The HVAC module is mounted to the lower side of the HVAC housing, between the HVAC distribution housing and the blower motor.

The HVAC module in this vehicle controls the Local Interface Network (LIN) communication for the Rear Climate Seat Switch Module, Comfort Seat Module Front Left, Comfort Seat Module Front Right, Comfort Seat Module Rear Left, Comfort Seat Module Rear Right and Comfort Steering Wheel Surface Module. For information about these heated/cooled systems, refer to the applicable heated/cooled system in HEATED/COOLED ACCESSORIES (SERVICE INFORMATION) .

OPERATION

The HVAC module utilizes integrated circuitry and information carried over the CAN-IHS data bus to monitor many sensors and switch inputs throughout the vehicle. In response to those inputs, the internal circuitry and programming of the HVAC module allows it to control electronic functions and features of the heating and A/C system.

For additional information about the HVAC module and its inputs and outputs. Refer to DESCRIPTION AND OPERATION, CONTROLS FRONT or DESCRIPTION AND OPERATION, CONTROLS REAR .

The HVAC module is diagnosed using a diagnostic scan tool. Prior to replacing an HVAC module, run the calibration procedure to verify that the concern is not an air door calibration issue. Refer to STANDARD PROCEDURE .

The HVAC module cannot be adjusted or repaired and must be replaced if inoperative or damaged.