A/C-Heater System

WARNING: This page is about a different car, the 2002 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

A single zone Heating, Ventilation, Air Conditioning (HVAC) system is available on this vehicle. The Heater Control Module (without A/C) performs the following:

Is fully addressable with the DRBIII(R).
Communicates over the PCI Bus.
Controls Blower Motor operation, providing 4 blower speeds.
Controls Heated Mirror operation (if equipped).
Controls Electronic Door Actuator operation.

The A/C-Heater Control Module performs the following:

Is fully addressable with the DRBIII(R).
Communicates over the PCI Bus.
Uses input from the Evaporator Temperature Sensor to prevent evaporator freeze up while maintaining optimum cooling performance.
Provides an A/C request to the PCM over the PCI Bus when compressor operation is desired.
Controls Blower Motor operation, providing 4 blower speeds.
Controls Heated Mirror operation (if equipped).
Controls electronic Door Actuator operation.

The Single-Zone HVAC system uses:

One 2-wire electronic Blend Door Actuator.
One 2-wire electronic Mode Door Actuator.
One 2-wire electronic Recirculation Door Actuator.

A simplified control system for operation of the mode, recirculation, and temperature control actuators provides positive positioning without the complexity of feedback from position sensors. The A/C-Heater Control Module knows the number of operating actuator revolutions required for full door travel as well as the number of actuator commutator pulses per revolution. Using these parameters, the A/C-Heater Control Module runs the actuator for the number of commutator pulses that correspond to the desired door position. To maintain accuracy, the system recalibrates itself periodically at known zero and full travel conditions. For additional information on A/C-Heater System, see MANUAL A/C-HEATER SYSTEMS - DAKOTA & DURANGO article in AIR CONDITIONING & HEATING.