Trooper LS 2WD V6-3.5L (2001)
Compressor Clutch: Initial Inspection and Diagnostic Overview
A/C Clutch Control Circuit Diagnosis
A/C Clutch Control Circuit Diagnosis
Circuit Description
When air conditioning and blower fan are selected, and if the system has a sufficient refrigerant charge, a 12-volt signal is supplied to the A/C request
input of the powertrain Control module (PCM). The A/C request signal may be temporarily canceled during system operation by the electronic
thermostat in the evaporator case. When the A/C request signal is received by the PCM, the PCM supplies a ground from the compressor clutch relay if
the engine operating conditions are within acceptable ranges. With the A/C compressor relay energized, voltage is supplied to the compressor clutch coil.
The PCM will enable the compressor clutch to engage whenever A/C has been selected with the engine running, unless any of the following conditions
are present:
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The throttle is greater than 90%.
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The ignition voltage is below 10.5 volts.
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The engine speed is greater than 4500 RPM for 5 seconds or 5400 RPM.
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The engine coolant temperature (ECT) is greater than 125 °C (257 °F).
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The intake air temperature (IAT) is less than 5 °C (41 °F).
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The power steering pressure switch signals a high pressure condition.
Diagnostic Aids
