A/C Request Signal Diagnosis

A/C Signal Diagnosis:

CIRCUIT DESCRIPTION
Turning "ON" the air conditioning supplies CKT 59 battery voltage to the A/C compressor clutch and to terminal "PB12" of the Powertrain Control Module (PCM) to increase and maintain idle speed.
The PCM does not control the A/C compressor clutch. Therefore, if A/C does not function, refer to Heating and Air Conditioning for diagnosis of the system.