Section 2 (Automatic HVAC Systems): Description

WARNING: This page is about a different car, the 2001 Dodge Grand Caravan and 2001 Chrysler Town & Country. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: To avoid injury from accidental air bag deployment, read and carefully follow all SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM procedures in AIR BAG SYSTEM SAFETY article in GENERAL SERVICING.

Automatic Temperature Control (ATC) system automatically maintains interior comfort level desired by driver, passenger and rear occupants. This is accomplished using Infrared (IR) sensors located in fascia of center vent on instrument panel and in rear zone control panel. The IR sensors independently monitor surface temperature of driver, passenger and rear occupant climate zones based on sensor inputs. ATC Heating, Vent and Air Conditioning (HVAC) system automatically adjusts air temperature, airflow volume, and amount of outside or recirculated air in vehicle cabin to maintain comfortable temperature level for all 3 climate zones under changing conditions. With front and rear systems is in automatic mode, AUTO will be displayed in ATC control panel Vacuum Fluorescent (VF) screen. Select temperature desired from rocker switches at ATC control panel for driver's zone, passenger's zone and rear occupant zone. ATC HVAC system will automatically maintain selected temperature levels for each climate zone.

The ATC system may also be operated manually in all modes and blower speeds. In manual mode, AUTO will not be illuminated in ATC control panel VF display window. HVAC system will perform similar to a manual HVAC system dependent upon manual control panel settings for A/C compressor, blower speed, recirculation mode and airflow mode. Blower motor speed is regulated by power module, in place of typical blower motor resistor. Power module regulates blower speed using Pulse Width Modulated (PWM) signal to ground blower motor circuit. PWM signal enables a full range of blower motor speed settings in manual mode or when controlled automatically in ATC mode.

Rear zone control panel is centrally located in headliner in rear occupant area. Rear zone control panel operation is overridden when rear control switch on ATC control panel is in OFF or AUTO positions. When rear control switch on ATC control panel is placed in REAR CONTROL position, rear zone control panel is enabled and will assume control of rear occupant climate zone and control rear HVAC unit operation. Rear zone control panel is equipped with rear IR sensor, digital temperature display, rocker switch for temperature setting, rotary switch for rear blower motor and rotary switch for rear mode settings. Rear HVAC unit contains separate blower motor, evaporator core, expansion valve and heater core. Plumbing for rear HVAC unit is routed along passenger side of vehicle for deliver refrigerant and coolant for to rear HVAC unit