P0532

CIRCUIT DESCRIPTION
The powertrain control module (PCM) monitors the high side refrigerant pressure through the A/C refrigerant pressure sensor. The PCM applies a 5 volt reference and a low reference to the sensor. Changes in the A/C refrigerant pressure cause the A/C refrigerant pressure input to the PCM to Vary. When the pressure is high, the signal voltage is high. When the pressure is low, the signal voltage is low. When the pressure is high the PCM commands the cooling fans on. When the pressure is too high or low the PCM will not allow the A/C compressor clutch to engage. When the DTC is set, the PCM does not allow the A/C compressor clutch to engage. This is done to protect the compressor. The PCM sends the A/C pressure data to the Dash Integration Module (DIM) over the class 2 communication line. The DIM will not request A/C compressor clutch engagement if the A/C pressure is too high.

The PCM monitors the A/C refrigerant pressure sensor signal circuit to detect signal voltages outside of the possible range of the sensor. When the PCM detects an A/C pressure signal that is excessively low, DTC P0532 will set.

CONDITIONS FOR RUNNING THE DTC
The engine is running

CONDITIONS FOR SETTING THE DTC
^ A/C pressure of less than 0.1 Volts
^ The condition must be present for more than 5 seconds

ACTION TAKEN WHEN THE DTC SETS
^ The PCM stores the DTC information into memory when the diagnostic runs and fails. The 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.
^ Use a scan tool to clear the diagnostic trouble code.

DIAGNOSTIC AIDS

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

If DTC P0532 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 1-9:

Steps 10-16:

The numbers below refer to the step numbers on the diagnostic table.
3. Tests for the proper operation of the circuit in the low voltage range.
4. 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.
5. Tests for a short to voltage in the 5 volt reference circuit.