Electra Park Avenue V6-231 3.8L VIN 3 FI (1988)
Diagnostic Switch
Microprocessor
The microprocessor retains the operating mode, blower mode, and temperature settings when the Ignition is turned off. They are retained for up to 30
minutes, after which, when the ignition is turned on, the microprocessor will reset to the AUTO-AUTO operating and blower modes; the previously
set temperature will still be retained.
An additional function of the microprocessor is that of system self-diagnosis. Faults in the temperature sensor circuits and temperature valve control
circuit are identified when the A/C control assembly is set to the diagnostic mode. Diagnostic codes are displayed on the VF display. If the system
does not have an identifiable fault, a 00 code will be displayed. Diagnostic mode activation and fault code identification are fully described under Air
Door Actuators. Refer to Air Door Actuators / System Diagnosis / Procedures / Delivery and Temperature Controls. See: Air Door/Air Door Actuator
/ Motor/Testing and Inspection
