P0530

Diagnostic Chart:

Wiring Diagram:

Circuit Description

The A/C refrigerant pressure sensor responds to changes in A/C refrigerant high side pressure. This input indicates how much load the A/C compressor is putting on the engine and is one of the factors used by the Powertrain Control Module (PCM) to determine the Idle Air Control (IAC) position for idle speed. The circuits consist of a 5 V reference and a ground, both provided by the PCM, and a signal from the sensor. The signal is a voltage which is proportional to A/C pressure. The sensors operating range is between 0 and 459 psi. At 0 psi, the signal voltage will be about 0.1 V, varying to about 4.9 V at 459 psi.

Conditions for Setting the DTC

^ A/C refrigerant sensor pressure is greater than 453 psi (4.94 V) with A/C requested.

Or

^ A/C refrigerant sensor pressure is greater than 363 psi (4.0 V) with A/C not requested.

Or

^ A/C refrigerant sensor pressure is less than 0 psi (0.20 V) when Intake Air Temperature (IAT) is greater than 0°C (32°F) and DTC's P0112 or P0113 are not set.

Or

^ A/C refrigerant sensor pressure is less than 0 psi (0.10 V) when Air Temperature (IAT) is greater than 0°C (32°F) and DTCs P0112 or P0113 are set.

^ Any of the above conditions met for 15 seconds.

Action Taken When the DTC Sets

^ The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer.

^ A history DTC is stored.

^ The PCM will disable the A/C compressor clutch.

Conditions for Clearing the MIL/DTC

^ A history DTC will clear after 40 consecutive warm up cycles without a fault.

^ DTC(s) can be cleared by using a scan tool.

Diagnostic Aids

^ An intermittent DTC P0530 set along with a DTC P1406 indicates that the ground circuit is shorting to the 5 volt reference circuit. When this happens, the EGR Actual Position on the scan tool will display an incorrect value. Check the wiring harness for being rubbed through and shorting together or for a faulty A/C refrigerant pressure sensor.

^ DTC P0530 sets when the signal voltage falls outside the normal possible range of the sensor. If the actual pressure of the A/C system matches the scan tool readings, repair any A/C pressure problems before using this table. Refer to Heating and Air Conditioning.

^ Any circuitry, that is suspected as causing the intermittent complaint, should be thoroughly checked for the following conditions:

- Backed out terminals.

- Improper mating of the terminals.

- Broken locks.

- Improperly formed or damaged terminals.

- Poor terminal to wiring connections.

- Physical damage to the wiring harness.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored on the scan tool for later reference.

2. If the MAP or Throttle Position (TP) sensor DTC is set, the malfunctioning circuit is diagnosed in these tables, refer to the appropriate table.

10. An open or poor connection in a shared sensor ground circuit will cause other DTCs to be set. If no other DTCs were set, the fault must be between the sensor and the circuit splice.

12. Determines if the low voltage signal was from the sensor or the signal circuit. Jumping the signal circuit to the 5 volt reference checks the circuits, connections and the PCM.

13. An open in a shared 5 volt reference circuit can cause other DTCs to be set. If no other DTCs were set, the circuit must be open between the sensor and the circuit splice.

15. Replacement PCMs must be reprogrammed. Refer to latest GM Techline information for programming procedures.

26. If no malfunction have been found at this point and no additional DTCs were set, refer to Diagnostic Aids for additional checks and information.