P1546

CIRCUIT DESCRIPTION
The PCM will activate the A/C clutch relay when the PCM detects that A/C has been requested. When the PCM activates the relay, voltage should be present at both the A/C compressor clutch and the A/C compressor clutch supply voltage circuit at the PCM. If voltage is not detected when A/C is requested this DTC sets.

CONDITIONS FOR RUNNING THE DTC
The ignition is turned ON.

CONDITIONS FOR SETTING THE DTC
^ The PCM detects that A/C has been requested.
^ The PCM commands the A/C compressor clutch driver ON.
^ The PCM does not detect a voltage on the A/C compressor clutch supply voltage circuit that supplies voltage to the A/C compressor clutch.
^ 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 fault-free ignition cycles.
^ The DTC can be cleared with a scan tool.

TEST DESCRIPTION

Steps 1-11:

Steps 12-13:

The numbers below refer to the step numbers on the diagnostic table.
3. Verifies that battery voltage is supplied to the A/C compressor clutch relay.
4. Tests if the A/C relay is at fault or the A/C compressor clutch supply voltage circuit is at fault.
5. If the A/C clutch feedback signal parameter displays OFF, this indicates the PCM does not recognize voltage from the A/C compressor clutch supply voltage circuit.
6. Tests for a high resistance or an open.
12. Perform the recalibration procedure for the powertrain control module.