Aspen 4WD V8-5.7L Hybrid (2009)
Control Assembly: Description and Operation
Front - Manual Single Zone
MANUAL SINGLE ZONE
The A/C-heater control (1) for the Manual Temperature Control (MTC) single zone heating-A/C system allows one temperature setting for the entire
vehicle. All controls are identified by ISO graphic symbols.
The A/C-heater control and integral computer is located in the instrument panel and contains:
-
a rotary control knob for rear window washer operation and rear window wiper speed selection (2).
-
a slider control knob for temperature control of the discharged air (3).
-
a rotary control knob for fan speed selection and turning the heater-A/C system off (4).
-
a rotary control knob for mode control of the discharged air (5).
-
a push button A/C on/off control (6). The Snowflake button contains an LED that illuminates when the A/C system is in operation.
-
a push button rear window defogger on/off control (7). The button contains an LED that illuminates when the rear window defogger system is in
operation.
The A/C-heater control for the manual single zone heating and A/C system is diagnosed using a scan tool See: Powertrain Management/Computers and
Control Systems/Testing and Inspection/Diagnostic Trouble Code Tests and Associated Procedures.
Prior to replacing an 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 A/C-heater control cannot be repaired or adjusted and must be replaced if inoperative or damaged. The illumination lamps (8) and control knobs are
available for service replacement.
The A/C-heater control utilizes integrated circuitry and information carried on the Controller Area Network (CAN) B bus to monitor many sensors and
switch inputs throughout the vehicle. In response to those inputs, the internal circuitry and programming of the A/C-heater control allows it to control
electronic functions and features of the MTC heating-A/C system.
The inputs received by the A/C-heater control of the MTC heating-A/C system on the CAN B bus are as follows:
-
Ambient Air Temperature
-
Dimming
-
Engine Coolant Temperature
-
Refrigerant Pressure
-
Vehicle Identification Number
-
Vehicle Odometer
-
Vehicle Speed
The messages broadcasted by the A/C-heater control of the MTC heating-A/C system on the CAN B bus are as follows:
-
A/C Request
-
A/C Select
-
Rear Washer Request
-
Rear Window Defogger (EBL) Request