P1539

CIRCUIT DESCRIPTION
The PCM will activate the A/C clutch relay when the PCM detects an A/C requested. Voltage is present at both A/C compressor clutch and the A/C clutch status terminal at the PCM when the relay is activated. A DTC P1539 sets if the PCM detects a voltage on the A/C compressor clutch supply voltage circuit when the system had not requested the A/C. A short to voltage on the A/C compressor clutch supply voltage circuit, or the A/C relay contacts are stuck, sets a DTC P1539.

CONDITIONS FOR RUNNING THE DTC
The A/C is OFF.

CONDITIONS FOR SETTING THE DTC
^ The PCM detects a voltage on the A/C compressor clutch supply voltage circuit when the A/C is not requested.
^ The condition is present for at least 20 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will not illuminate the Malfunction Indicator Lamp (MIL).
^ The PCM stores the failure records.
^ The A/C compressor clutch is disabled.

CONDITIONS FOR CLEARING THE DTC
^ The DTC will become history if the PCM no longer detects a failure.
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared with a scan tool.

TEST DESCRIPTION

Steps 1-8:

The numbers below refer to the step numbers on the diagnostic table.
3. Verifies the condition is present.
4. Determines if the A/C compressor clutch relay is at fault.
5. Determines if the PCM is at fault or the A/C compressor clutch supply voltage circuit is at fault.
7. Perform the recalibration procedure for the powertrain control module.