P0530

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 disable the A/C compressor clutch when the A/C system pressure is out of range. The PCM also uses A/C refrigerant pressure sensor to enable the engine coolant fans when the A/C refrigerant pressure is high.
The PCM supplies a 5 volt reference, a signal circuit, and a ground circuit to the A/C refrigerant pressure sensor. As the A/C pressure increases or decreases, the resistance of the sensor changes and varies the amount of signal voltage detected by 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. When the pressure is out of range (high or low) for a predetermined time, the PCM disables the A/C compressor clutch and sets a DTC P0530.When a DTC P0530 sets, the PCM disables the A/C compressor clutch in order to prevent compressor damage from occurring.

Conditions for Running the DTC
The PCM detects an A/C request.

Conditions for Setting the DTC
^ The A/C refrigerant pressure sensor indicates A/C refrigerant pressure is below -8 psi for 5 seconds.
^ The A/C refrigerant pressure sensor indicates A/C refrigerant pressure is above 448 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.
^ The PCM disables the A/C compressor clutch.

Conditions for Clearing the MIL/DTC
^ A History DTC will clear after forty 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/TAC module connector surfaces before servicing the PCM/TAC module. Inspect the PCM/TAC module connector gaskets when diagnosing/replacing the modules. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM/TAC modules.
^ For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616-A. Using this kit prevents damage to the harness/component terminals.
^ The following may cause an intermittent:
- Poor connections.
- Mis-routed harness.
- Rubbed through wire insulation.
- Broken wire inside the insulation.
^ If the test did not fail this ignition cycle, move the related electrical harnesses and the connectors while monitoring a scan tool.
^ Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This isolates when the DTC failed.
^ For an intermittent, refer to Symptoms. Symptom Related Diagnostic Procedures

Test Description
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 failure record data in order to determine when the DTC P0530 set.
5. If the A/C pressure/voltage 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 verifies the integrity of the A/C refrigerant pressure sensor signal circuit.
11. If you have thoroughly inspected the 5.0 volt reference circuit (for opens, shorts to ground, PCM connections etc.) and is OK, then replace the PCM.
12. If you have thoroughly inspected the ground circuit for opens and the PCM connections are OK, then replace the PCM.