PCM to Body Function Controller (BFC) A/C Clutch Data

A/C Clutch Mode - Range Clutch Enable. Req/A/C Req. Off/Off, Low Voltage/ Off, High Temp /Off, High Press./Off, Low Ambient/Off, Low RPM:
The message displayed refers to the Class 2 serial data communication message from the Powertrain Control Module (PCM) to the Body Function Controller (BFC) as to the current state of the A/C Compressor Clutch. The Powertrain Control Module (PCM) performs the following functions:
^ Prevent Compressor Overspeed
^ Limit Compressor Speed (Park & Neutral)
^ Detect Defective Transducer
^ Drive Compressor Clutch
^ Perform Anti slug

The Body Function Controller (BFC) performs the following functions:
^ Limit Low Speed Compressor Operation
^ Prevent Clutch Slippage (monitor voltage)
^ High Coolant Temperature
^ Monitor for Overpressure
^ Determine Low Ambient
^ Control Compressor Clutch

Clutch Enable Req (Clutch Enable Requested) display means the Powertrain Control Module (PCM) is driving the A/C Clutch. A/C Req. Off (A/C Requested Off) display means the Powertrain Control Module (PCM) is not driving the A/C Clutch. Off, Low Voltage display means the Powertrain Control Module (PCM) is not driving the A/C Clutch because of low battery voltage (10 volts or less). Off, High Temp display means the Powertrain Control Module (PCM) is not driving the A/C Clutch because of high Engine Coolant Temperature (above 121°C [250°F]). Off, High Press. display means the Powertrain Control Module (PCM) is not driving the A/C Clutch because of high A/C Compressor Outlet Pressure (above 2928 kPa [424 psi]). Off, Low Ambient display means the Powertrain Control Module (PCM) is not driving the A/C Clutch because of Low Ambient Pressure (below 227 kpa [33 psi]). Off, Low RPM display means the Powertrain Control Module (PCM) is not driving the A/C Clutch because of Low Engine RPM (4 cylinder - below 465 RPM, 6 cylinder - below 440 RPM).