With Manual AC

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 powertrain control module (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 A/C refrigerant pressure sensor operates like other 3 wire sensors. The PCM applies a 5 volt reference and a sensor ground to the sensor. Changes in the A/C refrigerant pressure will cause the A/C refrigerant pressure input to the PCM to vary. The PCM monitors the A/C refrigerant pressure sensor signal 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 the 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 RUNNING THE DTC
The engine is running.

CONDITIONS FOR SETTING THE DTC
^ The A/C refrigerant pressure sensor signal voltage is less than 0.1 volt.
^ OR
^ The A/C refrigerant pressure sensor signal voltage is more than 4.9 volts.
^ Either of the above conditions are present for more than 20 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 disables the A/C compressor clutch.
^ 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 DTC
^ A History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The current DTC will clear when the diagnostic runs and does not fail.
^ Use a scan tool in order to clear the diagnostic trouble code.

DIAGNOSTIC AIDS

IMPORTANT: Be sure to verify that the PCM engine grounds are secure and clean.

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

If the problem is intermittent, refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.

TEST DESCRIPTION

Steps 1-7:

Steps 8-17:

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

4. Tests for the proper operation of the circuit in the low voltage range.
5. Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
6. Tests for a short to voltage in the 5 volt reference circuit.