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Test D: The Air Conditioning (A/C) Is Always On

PINPOINT TEST D: THE AIR CONDITIONING (A/C) IS ALWAYS ON


D1-D5:






D5-D6:






NOTE: Before carrying out the following test, diagnose any PCM DTCs.

Normal Operation
Under normal operation, the function selector switch is supplied voltage through circuit CBP27 (GN/BN). When any mode requiring A/C is selected, the function selector switch sends voltage to the A/C high pressure switch through circuit CH443 (GN/OG). Voltage is then supplied from the A/C high pressure switch to the A/C cycling switch through circuit CH423 (YE). The voltage is then supplied from the A/C cycling switch to the PCM through circuit CH425 (GN/BU).

Voltage is supplied to the A/C clutch relay switch through circuit SBB25 (RD). When the relay is energized, voltage is sent to the A/C clutch through circuit CH401 (VT/WH). The A/C clutch is grounded through circuit GD121 (BK/YE).

Possible Causes
- A short to voltage in circuits CH401 (VT/WH), CH425 (GN/BU), CH423 (YE) or CH443 (GN/OG)
- PCM
- Function selector switch
- A/C control relay
- A/C clutch diode
- A/C clutch air gap