P0532

DTC P0531, P0532, or P0533

Diagnostic Instructions

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

DTC Descriptors
DTC P0531
- Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit

DTC P0532
- Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit Low Voltage

DTC P0533
- Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit High Voltage

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 V reference and a low reference to the sensor. Changes in the A/C refrigerant pressure cause the sensor signal to the ECM to vary. When the pressure is high, the signal voltage is high. When the pressure is low, the signal voltage is low. When pressure is high, the ECM commands the cooling fans on.

Conditions for Running the DTC

* Engine is running.
* Any of the conditions for setting the DTC are met for 15 seconds.
* Battery voltage is between 11-18 V.

Conditions for Setting the DTC

* The ECM detects that the A/C pressure is less than 1 psi (0.01 V).
* The ECM detects that the A/C pressure is more than 428 psi (4.92 V).

Action Taken When the DTC Sets

This is a type D DTC.

Conditions for Clearing the DTC

This is a type D DTC.

Diagnostic Aids

A malfunction within the refrigerant system causing high pressure can cause this DTC to set.

Reference Information
Schematic Reference

HVAC Schematics
Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1 A4
Description and Operation

Automatic HVAC Description and Operation
Electrical Information Reference

* Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference

Control Module References Control Module Referencesfor scan tool information

Circuit/System Verification

Vehicle in Service Mode, observe the scan tool A/C High Side Pressure Sensor parameter in the ECM data list. The reading should be between 6.8 kPa (1 psi) and 2950 kPa (428 psi).

Circuit/System Testing

1. Vehicle OFF, disconnect the B1 A/C refrigerant pressure sensor harness connector.
2. Vehicle OFF, test for less than 10 ohm between the low reference circuit terminal 1 and ground.

• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

3. Vehicle in Service Mode, test for 4.8-5.2 V between the 5 V reference circuit terminal 2 and ground.

• If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
• If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

4. Verify the scan tool A/C High Side Pressure Sensor parameter is less than 5 kPa (34.4 psi).

• If greater than the specified range, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the K20 ECM.

5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 2. Verify the scan tool A/C High Side Pressure Sensor parameter is greater than 2950 kPa (428 psi).

• If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

6. If all circuits test normal, test or replace the B1 A/C refrigerant pressure sensor.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* HVAC Component Replacement Reference
* Control Module References Control Module Referencesfor ECM replacement, programming and setup