P0533
DTC P0532 or P0533Diagnostic Instructions
^ Perform the [Diagnostic System Check - Vehicle Diagnostic Information] prior to using this diagnostic procedure. Diagnostic System Check - Vehicle Diagnostic Information
^ Review [Strategy Based Diagnosis] for an overview of the diagnostic approach. Strategy Based Diagnosis
^ [Diagnostic Procedure Instructions - Vehicle Diagnostic Information] provides an overview of each diagnostic category. Diagnostic Procedure Instructions - Vehicle Diagnostic Information
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/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 low, the signal voltage low. When the pressure high, the ECM commands the cooling fans on. When pressure too high or too low, the ECM will not allow the A/C compressor clutch to engage.
Conditions for Running the DTC
^ The engine running.
^ The battery voltage between 11-18 volts.
Conditions for Setting the DTC
^ The ECM detects that the A/C pressure less than 1 psi (0.01 volt).
^ The ECM detects that the A/C pressure more than 425 psi (4.90 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 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.
Diagnostic Aids
A malfunction within the refrigerant system causing high pressure can cause this DTC to set.
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 4.90 volts (1 and 425 psi), 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 between the low reference circuit terminal and ground.
^ 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 4.8-5.2 volts between the 5-volt reference circuit terminal and ground.
^ If less than 4.8 volts, 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 5.2 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 less than 0.1 volt (1 psi).
^ If greater than 0.1 volt (1 psi), test the signal circuit terminal for a short to voltage. If the circuit tests normal, replace the ECM.
5. Install a 3 A 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 greater than 4.90 volts (425 psi).
^ If less than 4.90 volts (425 psi), 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.
Repair Instructions
Perform [Diagnostic Repair Verification - Vehicle Diagnostic Information] after completing the diagnostic procedure. Diagnostic Repair Verification - Vehicle Diagnostic Information
^ [Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement]