P1545

CIRCUIT DESCRIPTION
Ignition voltage is supplied directly to the A/C compressor clutch relay. The powertrain control module (PCM) controls the relay by grounding the control circuit through an internal solid state device called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which is monitored by the PCM. When the PCM is commanding a component ON, the voltage of the control circuit should be near 0 volts. When the PCM commands the control circuit to a component OFF, the voltage potential of the circuit should be near the battery voltage. If the fault detection circuit senses an unexpected voltage, this DTC will set.

CONDITIONS FOR RUNNING THE DTC
^ The engine is running.
^ System voltage is between 8-16 volts.
^ The PCM driver is activated.

CONDITIONS FOR SETTING THE DTC
^ The PCM detects an incorrect voltage level on the output circuit that controls the A/C compressor clutch relay.
^ The condition exists for at least 10 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 clear after 50 fault-free ignition cycles.
^ The DTC can be cleared with a scan tool.

DIAGNOSTIC AIDS
If the condition is not present, refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.

TEST DESCRIPTION

Steps 1-13:

The numbers below refer to the step numbers on the diagnostic table.
2. Listen for an audible click when the A/C compressor clutch relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. Tests for voltage at the switch side of the A/C compressor clutch relay. The 10-amp fuse supplies power to the switch side of the A/C compressor clutch relay.
4. Verifies that the powertrain control module is providing ground to the A/C compressor clutch relay.
5. Tests if ground is constantly being applied to the A/C compressor clutch relay.
6. Tests for a short to voltage or for an open.
12. Perform the calibration procedure for the powertrain control module.