CHART C-10, A/C CLUTCH CONTROL CKT DIAGNOSIS 2.5/2.8L (1 Of 2)

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The ECM controls the A/C clutch engagement to improve idle quality and performance by delaying A/C clutch engagement until idle speed is increased, disengages clutch when idle speed is too low, and smooths cycling of compressor by providing additional fuel the instant A/C clutch is engaged.

NOTE: Test numbers refer to test numbers on diagnostic charts.

Checks for low A/C refrigerant charge, causing A/C clutch not to engage.
This and the following tests checks for faulty A/C control relay.

Fig 1: A/C Clutch Circuit (2.5L & 2.8L), Schematic

Courtesy of GENERAL MOTORS CORP.

Fig 2: A/C Clutch Circuit (2.5L & 2.8L), Flow Chart, (1 Of 2)

Courtesy of GENERAL MOTORS CORP.