Heating and Air Conditioning - Description

DESCRIPTION

An electronic Manual Temperature Control (MTC) single zone type heating-A/C system, electronic MTC heater-only system and an electronic Automatic Temperature Control (ATC) single zone type heating-A/C system are available on this model, depending on market.

To maintain the performance level of the Heating, Ventilation and Air Conditioning (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. See Cooling for more information before opening or attempting any service to the engine cooling system.





The heating-A/C system combines A/C, heating, and ventilating capabilities in a single HVAC housing mounted within the passenger compartment beneath the instrument panel. All vehicles are equipped with a common HVAC housing that includes:

- Blend-air door and actuator (1)
- Evaporator temperature sensor (2) (when A/C equipped)
- A/C evaporator (3) (when A/C equipped)
- Mode-air doors (4)
- Mode door actuator (5)
- Recirculation-air door and actuator (6) (when A/C equipped)
- Particulate air filter (7) (when equipped)
- Blower motor (8)
- Blower motor resistor or power module (9) (depending ATC/MTC application)
- Heater core (10)

On heater-only systems, the A/C evaporator is omitted from the HVAC housing and is replaced with an air restrictor plate.

NOTE: An electric positive temperature coefficient (PTC) heater is used on vehicles when equipped with the 2.2L diesel engine. The PTC heater unit compensates for the lower engine coolant temperatures produced by the diesel engine. The PTC heater unit is mounted in the HVAC air distribution housing, downstream of the heater core.

Based upon the system mode selected, conditioned air can exit the HVAC 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 of the distribution housing. Once the conditioned air exits the HVAC housing, it is further directed through molded plastic ducts to the various outlets within the vehicle interior. These outlets and their locations are as follows:

- Defroster Outlet - A single large defroster outlet is located in the center of the instrument panel, near the base of the windshield.
- Side Window Demister Outlets - There are two side window demister outlets, one is located at each outboard end of the instrument panel top cover, near the belt line at the A-pillars.
- Panel Outlets - There are four panel outlets in the instrument panel, one located near each outboard end of the instrument panel facing the rear of the vehicle and two located near the top of the instrument panel center bezel.
- Front Floor Outlets - There are two front floor outlets, one located on each side the floor panel center tunnel behind the instrument panel.
- Rear Seat Floor Outlets - There are two rear seat floor outlets, one located on each side of the floor panel near the front of each rear seat foot well.