Manual Temperature Control (MTC)
DESCRIPTION
The MTC Heating, Ventilation and Air Conditioning (HVAC) system is comprised of the following three subsystems, refer to the following for more information:
- Refer to PLUMBING, DESCRIPTION AND OPERATION (Orange)
- Refer to DISTRIBUTION, DESCRIPTION AND OPERATION (Light Blue)
- Refer to CONTROLS, DESCRIPTION AND OPERATION (Red)
OPERATION
The interior climate of the vehicle is controlled by acting on the three control knobs placed on the Air Conditioning (A/C) heater control which is located on the lower center instrument panel. Based upon the system mode selected, conditioned air can exit the standard A/C housing through one or a combination of the three main housing outlets: defrost, panel or floor. The defrost and panel outlets are located on the top of the HVAC air distribution housing and the floor outlets are located on each side and in the center of the distribution housing. Once the conditioned air exits the HVAC housing, it is then directed through molded plastic ducts to the various outlets within the vehicle interior.
The HVAC module is connected to the Controller Area Network - Interior High Speed (CAN-IHS) data bus and receives the information of the humidity sensor from the Instrument Panel Cluster (IPC) via CAN. The A/C activation request from the user and the heated rear window activation request must be sent to the Body Control Module (BCM) via CAN. The A/C request status and the actuator position are stored in the HVAC module. The system manages air recirculation, distribution and temperature using the actuators with potentiometer, for opening, closing and regulating the intermediate positions via electrical commands. The HVAC module controls the mixing temperatures through the temperature sensors located in the HVAC housing. The system manages the air temperature request by also monitoring solar radiation through a dedicated sensor located on the steering column opening cover. The HVAC manages activation of the rear window defroster.
To maintain the performance level of the HVAC system, the engine cooling system must be properly maintained. The use of a bug screen is not recommended. Any obstructions in front of the radiator or A/C condenser will reduce the performance of the A/C and engine cooling systems. The engine cooling system includes the radiator, thermostat, radiator hoses and the engine coolant pump.(Refer to 3.0L, COOLING SYSTEM, DESCRIPTION AND OPERATION or 3.6L, COOLING SYSTEM, DESCRIPTION AND OPERATION ) for more information before opening or attempting any service to the engine cooling system.