Front Control Panel

The front 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 rear fan speed selection and turning the rear heater-A/C system off (5).
- a rotary control knob for mode control of the discharged air (6).
- a push button A/C on/off control (7). 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 (8). The button contains an LED that illuminates when the rear window defogger system is in operation.

The front A/C-heater control cannot be repaired and, if faulty or damaged, it must be replaced. The illumination lamps (9) and control knobs are available for service replacement.

The A/C-heater control for the MTC single zone heating-A/C system is diagnosed using a scan tool.

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:
- Dimming
- Refrigerant Pressure
- Vehicle Identification Number
- Vehicle Odometer
- Engine Coolant Temperature
- Ambient Air Temperature
- 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 Window Defogger (EBL) Request
- Rear Washer Request
- Rear Wiper Request