Diagnostic Aids

The following conditions must be met in order for the ECM to turn on the compressor clutch:

• Battery voltage is between 9-18 volts
• Engine coolant temperature (ECT) is less than 123°C (253°F)
• Engine speed is less than 4,760 RPM
• Engine speed is more than 600 RPM
• A/C high side pressure is between 2929-269 kPa (425-39 psi)
• Throttle position is less than 100 percent
• Evaporator temperature is greater than 0°C (32°F)
• ECM does not detect excessive torque load
• ECM does not detect insufficient idle quality