For 1990-2009 cars
Engine Controls Components
Engine Data Sensors
OBD II Symbol Description Notice
Powertrain Control Module Connector End Views
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

The A/C refrigerant pressure sensor responds to the changes in the A/C refrigerant high side pressure. This input indicates the amount of load the A/C compressor is putting on the engine, and is one of the factors used by the Powertrain Control Module (PCM) in order to determine the idle air control (IAC) position for the 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 the A/C pressure. The sensor's operating range is between 0 and 459 psi. At 0 psi, the signal voltage will be about 0.1 V, and vary up to about 4.9 V at 459 psi.

### Conditions for Running The DTC

The A/C refrigerant pressure is more than 453 psi (4.92 V) with the A/C requested,

OR:

The A/C refrigerant pressure is more than 363 psi (3.98 V) with the A/C not requested.

### Conditions for Setting the DTC

Any of the above conditions are met for 15 seconds.

### Action Taken When the DTC Sets

• | The PCM will record the operating conditions at the time during which the diagnostic fails. This information will store in the Failure Records buffer.

• | A history DTC stores.

• | 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.

• | Use a scan tool to clear the DTCs.

### Diagnostic Aids

• | The DTC P0530 sets when the signal voltage falls outside of the normal 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.

• | Inspect any suspected circuitry for the following conditions:

- | Any backed out terminals

- | Any incorrect mating of the terminals

- | Any broken locks

- | Any incorrectly formed or damaged terminals

- | Any poor terminal-to-wiring connections

- | Any physical damage to the wiring harness

### Test Description

The numbers below refer to step numbers on the diagnostic table.

1. The replacement PCM must be programmed and the Crankshaft Position System Variation Learn procedure must be performed.

#### DTC P0530 A/C Refrigerant Pressure Sensor Circuit

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Use a scan tool in order to observe the A/C high side pressure. Is the pressure more than the specified value? | 3.0 V (279 psi) | Go to Step 3 | Go to Diagnostic Aids
3 |

1. Turn off the ignition.
2. Disconnect the A/C refrigerant pressure sensor.
3. Connect a DMM to B+.
4. Probe the A/C refrigerant pressure sensor ground circuit.

Does the voltage equal the specified value?

B+

Go to Step 4

Go to Step 5

4 |

1. Connect the DMM to ground.
2. Probe the signal circuit of the A/C refrigerant pressure sensor .

Is the voltage more than the specified value?

0.5 V

Go to Step 6

Go to Step 7

5 |

1. Test the ground circuit of the A/C refrigerant pressure sensor for the following conditions:

• | An open

• | Any poor connections

2. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 8

6 |

1. Test the signal circuit of the A/C refrigerant pressure sensor for the following conditions:

• | A short to B+

• | A short to the 5 volt circuit

2. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 8

7 | Replace the A/C refrigerant pressure sensor. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement . Did you complete the repair? | -- | Go to Step 9 | --
8 | Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the repair? | -- | Go to Step 9 | --
9 |

1. Use a scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK