P0530

Engine Controls Schematics: A/C Compressor Control:

CIRCUIT DESCRIPTION
The A/C system uses an A/C refrigerant pressure sensor mounted in the high side of the A/C system to monitor A/C refrigerant pressure. The PCM utilizes this information in order to turn ON the engine coolant fans when the A/C refrigerant pressure is high. The PCM supplies a 5.0 volt reference and ground to the sensor. As the A/C pressure increases or decreases, the resistance of the sensor changes and varies the amount of signal returning to the PCM. The PCM monitors the A/C refrigerant pressure sensor signal circuit and can determine when the A/C pressure is too high or too low. The PCM disables the A/C compressor clutch and sets a DTC P0530 when the pressures are out of range (high or low) for a predetermined time. The PCM disables the A/C compressor in order to prevent A/C compressor damage.

CONDITIONS FOR RUNNING THE DTC
The PCM detects an A/C request.

CONDITIONS FOR SETTING THE DTC
A/C refrigerant pressure sensor indicates A/C refrigerant pressure is below 3.0 psi for 5 seconds.
OR
A/C refrigerant pressure sensor indicates A/C refrigerant pressure is above 445 psi for 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM stores the DTC information into memory when the diagnostic runs and fails.
^ The Malfunction Indicator Lamp (MIL) will not illuminate.
^ The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ A History DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
^ A last test failed (Current DTC) will clear when the diagnostic runs and does not fail.
^ Use a scan tool in order to clear the MIL/DTC.

DIAGNOSTIC AIDS

IMPORTANT:
^ Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.
^ For any test that requires probing the PCM or a component harness connector, use the J 35616-A connector test adapter kit. Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Diagrams.

If the test did not fail this ignition cycle, move the related electrical harnesses and the connectors while monitoring a scan tool.

For an intermittent, refer to Symptoms. Symptom Related Diagnostic Procedures

TEST DESCRIPTION

Steps 1 - 11:

Steps 12 - 16:

The numbers below refer to the step numbers on the diagnostic table.
3. The normal A/C voltage is between 1.0 and 1.8 volts. If the A/C voltage is within the range, review the Freeze Frame/Failure Records data in order to determine when the DTC P0530 set.
5. If the A/C pressure/volt age stays high after disconnecting the A/C refrigerant pressure sensor electrical connector, this indicates the signal circuit is shorted to a voltage.
7. This step tests for a good ground circuit.
8. This step tests the integrity of the A/C refrigerant pressure sensor signal circuit.
11. If you have thoroughly tested the 5 volt reference circuit (for opens, shorts to ground, PCM connections etc.) and tests OK, then replace the PCM.
12. If you have thoroughly tested the ground circuit for opens and the PCM connections are OK, then replace the PCM.