Diagnostic Pointers and Parameters

DIAGNOSTIC POINTERS AND PARAMETERS

INPUTS
The inside, outside temperature, and sun load sensors are inputs to the H-A/C control. These inputs along with the feedback from the electric actuator potentiometer are used by the H-A/C control to determine the correct temperature valve position, blower motor speed and air delivery mode.

OUTPUTS
The H-A/C control sends outputs to the blower motor control module, the rear defogger relay, PCM, electric actuator and vacuum/electric solenoid to control the ACAC system.

OVERRIDES
The program number (pointer number "-05") is displayed as a number between 0 and 255 in the diagnostic mode. It is shown where the climate control set temperature is normally displayed. This number represents various levels of heating and cooling effort. As it first appears, the number displayed is the program number currently being used by the ACAC system. As operating conditions and other inputs change, this number will automatically change to control the desired temperature setting.

The automatic calculation of program number can be bypassed by manual override using the "TEMP Increase" and TEMP Decrease" switch on the H-A/C control panel. Pressing the "TEMP Increase" switch will force the program number to increase at a three increment rate until a value of "253 to 255" is reached. "255" represents the maximum amount of beat the ACAC system can produce at that given engine temperature.

Pressing the "TEMP Decrease" switch will force the program number to decrease until the value of "0 to 2" is reached which represents the maximum amount of air conditioning the system can produce. This override has a wrap-around feature, if the program number sequence is continued past either end.