Durango 2WD V8-4.7L Flex Fuel (2009)
Control Assembly: Description and Operation
Front - Automatic Dual Zone With Rear Heat and A/C
AUTOMATIC DUAL ZONE WITH REAR HEAT AND A/C
The Automatic Temperature Control (ATC) dual zone front heating-A/C system allows both the driver and the front seat passenger the ability to
individually regulate air temperature for their side of the vehicle. Primary control for the rear heater-A/C system is also on the front A/C-heater control.
An infrared sensor located in the overhead console detects thermal radiation emitted by the front seat occupants and their surroundings. All controls are
identified by ISO graphic symbols.
FRONT CONTROL PANEL
The front A/C-heater control and integral computer (1) is located in the instrument panel and contains the following:
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a push button Auto mode control (2).
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Two rocker switch controls (3 and 11) to select both of the front and the rear comfort temperatures from 15° to 29° C (60° to 85° F). Comfort
temperatures for each zone are shown in the Vacuum-Fluorescent (VF) digital display (4). If the set temperatures are 15° C (60° F) and down (-) is
pressed, the A/C-heater control will attempt to achieve the lowest temperature possible, but the display will show LO. If the set temperatures are
29° C (85° F) and up (+) is pressed, the A/C-heater control will attempt to achieve the highest temperature possible, but the display will show
HIGH. Temperatures can be displayed in either Metric or Fahrenheit, which is selected from the overhead console.
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a rotary control knob with integral push button control for front fan speed selection that can override the automatic controls and on/off control
which allows the heating-A/C system to be completely turned off (5). The display is blank when the heater-A/C system is off, except for the ISO
rear window defogger symbol when the rear window defogger system is on.
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a push button A/C on/off control (6). An ISO Snowflake symbol appears in the display when the A/C system is in operation, whether under manual
or automatic control.
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a push button air recirculation control (7). An ISO Recirculation symbol appears in the display when the button is pressed, or when the system
exceeds 80 percent circulated air under automatic control (Gasoline models) or 100 percent circulated air under automatic control (HEV models),
due to high A/C demand.
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five push button mode controls (8). An ISO mode symbol appears in the display to show the current mode setting when each button is manually
pressed or selected by Auto mode.
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a push button rear window defogger on/off control (9). An ISO symbol appears in the display when the rear window defogger system is in
operation. The ISO symbol will appear on the display even with the heating-A/C system turned off.
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a rotary control knob for rear window washer operation and rear window wiper speed selection (10).
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a push button control for rear heating-A/C system operation (12).
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two illumination lamps for backlighting of the controls (13).
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computer logic that remembers the settings of the controls when the ignition is turned off and retains those settings after a restart. If the system is
off when the ignition is turned off it will be off when the engine is restarted, etc.
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computer logic that provides variable air recirculation under high temperature and humidity conditions. Because recirculation is generally
accompanied by increased fan noise, the proportion of recirculated to outside air gradually approaches full recirculation over a broad temperature
range.
The A/C-heater control for the ATC front dual zone heating-A/C system is diagnosed using a scan tool See: Testing and Inspection.
Prior to replacing the A/C-heater control, always perform the Actuator Calibration Test to verify the concern is not a heating A/C system issue . See:
Testing and Inspection/Component Tests and General Diagnostics/HVAC System Test
The front A/C-heater control cannot be adjusted or repaired and must be replaced if inoperative or damaged. The illumination lamps, rear wiper/wash
