The A/C control panel uses switches for selecting operating modes, in-vehicle temperature, blower motor speeds, and outside air temperature. Temperatures may be displayed in either Fahrenheit ( F) or Celsius ( C).
The assembly contains a microprocessor which receives signal input from panel switches, temperature sensors, and the air mix door feedback potentiometer in the programmer. Blower motor speed is also monitored. The control panel uses this input to position the air doors and control the blower motor speed. The microprocessor will retain all selected settings when the ignition is turned off.
The control panel microprocessor is also capable of self-diagnosis for some system circuits and sensors. If a fault is present, a trouble code will be set in memory. Diagnostic trouble codes can be displayed on the control panel.
If "EXT TEMP" indicator is flashing during first few seconds after engine is started, this indicates a trouble code set in memory. To enter self-diagnostics, turn ignition on with engine off.
Press hidden diagnostic button between "EXT TEMP" and "HI" buttons. To exit diagnostic mode, press "EXT TEMP", "WARM" and "COOL" buttons at same time or cycle ignition switch.
check control module and it plug
Monday, September 20th, 2010 AT 6:08 AM