GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Opel 🢒 2008 🢒 Antara 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P0532 or P0533

Diagnostic Instructions
    •  Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    •  Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P0532: Air Conditioning A/C Refrigerant Pressure Sensor Circuit Low Voltage

DTC P0533: Air Conditioning A/C Refrigerant Pressure Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

5-Volt Reference Voltage

P0532

P0532

P0533

--

A/C Refrigerant Pressure Sensor Signal

P0532

P0533

P0532

--

Low Reference

--

--

P0533

--

Circuit/System Description

The engine control module (ECM) monitors the high side refrigerant pressure through the A/C refrigerant pressure sensor. The ECM supplies a 5-volt reference and a low reference to the sensor. Changes in the A/C refrigerant pressure cause the A/C refrigerant pressure sensor signal to the ECM to vary. When the pressure is low, the signal voltage is low. When the pressure is high, the ECM commands the cooling fans on. When pressure is too high or too low, the ECM will not allow the A/C compressor clutch to engage.

Conditions for Running the DTC
    • Ambient temperature is greater than -10.5°C (13.1°F).
    • The Engine is running.
    • The Battery voltage is between 11-18 volts.

Conditions for Setting the DTC
    • The ECM detects that the A/C pressure is less than 0 psi (0.01 volts).
    • The ECM detects that the A/C pressure is more than 497 psi (4.94 volts).

Action Taken When the DTC Sets
    • The ECM will not illuminate the malfunction indicator lamp (MIL).
    • The ECM stores the failure records.
    • The A/C compressor clutch is disabled.

Conditions for Clearing the DTC
    • The history DTC will clear after 40 consecutive ignition cycles have occurred without a malfunction.
    • The DTC or DTCs can be cleared by using the scan tool.
    • The DTC will become history if the ECM no longer detects a failure.

Circuit/System Verification

Ignition ON, observe the scan tool A/C High Side Pressure parameter in the ECM. The reading should be between 0.1 and 4.9 volts and change with pressure.

Circuit/System Testing
  1. Ignition OFF, disconnect the A/C Refrigerant Pressure harness connector at the A/C Refrigerant Pressure Sensor.
  2. Ignition OFF, test for less than 1.0 ohm of resistance between the low reference circuit terminal and ground.
    3. ⇒If greater than 1.0 ohm, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  3. Ignition ON, test for 0.1-4.9 volts between the 5-volt reference circuit terminal and ground.
    4. ⇒If less than 0.1 volt, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    ⇒If greater than 4.9 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  4. Verify the scan tool A/C High Side Pressure Sensor parameter is less than 0.1 volt.
    5. ⇒If greater than 0.1 volt, test the signal circuit terminal for a short to voltage. If the circuit tests normal, replace the ECM.
  5. Install a 3-amp fused jumper wire between the signal circuit and the 5-volt reference circuit terminal. Verify the scan tool A/C Refrigerant High Side Pressure Sensor is greater than 4.9 volts.
    6. ⇒If less than 4.9 volts, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
  6. If all circuits test normal, replace the A/C Refrigerant Pressure Sensor.

Component Testing

Static Test

  1. Ignition OFF, disconnect the A/C Refrigerant Pressure Sensor harness connector at the A/C Refrigerant Pressure Sensor.
  2. Test for 0.721 kohms of resistance between the 5-volt reference and the low reference terminal.
    3. ⇒If the resistance is not equal to or close to the specified value, replace the A/C Refrigerant Pressure Sensor.
  3. Test for 0.721 kohms of resistance between the signal terminal and the low reference terminal.
    4. ⇒If the resistance is not equal to or close to the specified value, replace the A/C Refrigerant Pressure Sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement
    •  Control Module References for ECM setup, replacement, and programming.