A/C Request Signal Diagnosis

A/C Signal:

CIRCUIT DESCRIPTION
Turning "ON" the air conditioning supplies CKT 59 battery voltage to the A/C compressor clutch and to terminal "PB4" 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 the A/C for diagnosis of the system.