Programmer Description

The heater and A/C programmer contains a microprocessor which controls the electronic A/C system. The programmer receives electrical signals from the following components:
^ Heater
^ A/C control
^ Sun load sensors
^ Ambient temperature sensor
^ Inside temperature sensor
^ [1][2]Blower control module
^ Powertrain control module
^ Mode selector switch
^ Actuators

A microprocessor in the programmer processes the signals. The microprocessor then sends commands to the system components that control the following elements:
^ The A/C compressor clutch operation
^ The air intake location
^ The air discharge location
^ The air discharge temperature
^ The blower speed

The heater and A/C programmer also performs self-diagnosis functions for the electronic A/C system. When the system diagnostic mode is activated through a scan tool, these faults are displayed as a numeric Diagnostic Trouble Code (DTC).