Seville STS V8-4.6L VIN 9 (1998)
Powertrain Control Module (PCM): Description and Operation
PCM Controlled Air Conditioning
A/C System
A/C operation is requested by the ACM using a serial data (Class 2) message to the PCM. The PCM will ground the A/C relay allowing current to flow
through the A/C Compressor clutch coil. The PCM will disable or inhibit A/C compressor clutch operation during the following conditions:
^
High power steering load indicated.
^
Engine not running.
^
Engine at wide open throttle.
^
Outside temperature below approximately 4°C (40°F).
^
Certain PCM DTCs set.
The PCM will also engage the A/C compressor clutch during cranking in colder weather to prevent A/C slugging.
