The ECM will energize the A/C clutch whenever the engine
is running and the A/C has been requested, unless any of the following conditions
are met:
| • | A Wide Open Throttle (WOT) |
| • | The A/C head pressure is greater than 435 psi or less than
26 psi (as determined by the A/C refrigerant pressure sensor). |
| • | The ignition voltage is less than 9 volts |
Use the
Air Conditioning (A/C) Request Circuit Diagnosis
for diagnosing the A/C request, the load signal, and the compressor
control circuit only. Refer to Heating and Air Conditioning
or Climate Control Diagnosis
of Climate Control for diagnosing
the refrigerant portion of the system.
Use the Tech 2 in diagnosing the system. The ECM has the ability to
display the following parameters:
| • | The A/C request input to the ECM |
| • | The A/C compressor control |
