P0530

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The A/C system uses an A/C refrigerant pressure sensor mounted in the high pressure side of the A/C refrigerant system to monitor A/C refrigerant pressure. The PCM uses this information to turn ON the engine coolant fans when the A/C refrigerant pressure is high and to keep the compressor disengaged when A/C refrigerant pressure is excessively high or low.

The PCM applies a 5.0 volt reference and a sensor ground to the sensor. Changes in the A/C refrigerant pressure will cause the A/C refrigerant pressure signal input to the PCM to vary. The PCM monitors the A/C refrigerant pressure circuit and can determine when the signal is outside of the possible range of the sensor. When the signal is out of range (high or low) for a prolonged period of time, the PCM will set DTC P0530. When DTC P0530 is set, the PCM will not allow the A/C compressor clutch to engage. This is done to protect the compressor.

CONDITIONS FOR SETTING THE DTC

^ The engine is running.

^ A/C is requested.

^ The A/C High Side Pressure sensor signal voltage is less than 0.1 volt.

OR

^ The A/C refrigerant pressure sensor signal voltage is greater than 4.94 volts.

Either of the above conditions for longer than 20 seconds.

ACTION TAKEN WHEN THE DTC SETS

^ The PCM will not illuminate the Malfunction Indicator Lamp (MIL).

^ The PCM will store conditions which were present when the DTC set as Fail Records data only. This information will not be stored as Freeze Frame data.

^ A/C compressor operation will be disabled while the high or low pressure indication exists.

CONDITIONS FOR CLEARING THE MIL/DTC

^ A history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

^ DTC can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed.

DIAGNOSTIC AIDS

Check for the following conditions:

^ Poor connection at the PCM or the A/C refrigerant pressure sensor.

Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.

^ Damaged harness.

Inspect the wiring harness for damage.

^ If the harness appears to be OK, observe the A/C High Side Pressure display on the scan tool while moving connectors and wiring harnesses related to the A/C refrigerant pressure sensor. A change in the A/C High Side Pressure display will indicate the location of the malfunction.

IMPORTANT: Be sure to inspect PCM engine grounds for being secure and clean.

If DTC P0530 cannot be duplicated, reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

TEST DESCRIPTION

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

2. Normal A/C refrigerant pressure sensor signal voltage is between 0.1 and 4.8 volts. If A/C voltage is within range, review Fail Records data to determine the conditions that were present when DTC P0530 set.

4. If the A/C refrigerant pressure signal voltage stays high after disconnecting the A/C refrigerant pressure sensor electrical connector, the signal circuit is shorted to voltage or the PCM is malfunctioning.

20. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.