For 1990-2009 cars

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 load signal

• | The A/C compressor control