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P0533




DTC 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 each diagnostic category.

DTC Descriptors

DTC P0532 00

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

DTC P0533 00

-
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 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. When pressure is too high or too low, the ECM will not allow the activation of the A/C compressor.

Conditions for Running the DTC

Engine is running.

Conditions for Setting the DTC

P0532 00

The ECM detects a short to ground or open at the A/C pressure sensor signal circuit.

P0533 00

The ECM detects a short to voltage at the A/C pressure sensor signal circuit.

Action Taken When the DTC Sets

* The A/C compressor is disabled.

* The ECM will illuminate the malfunction indicator lamp (MIL).

Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

Reference Information

Schematic Reference

HVAC Schematics Electrical Diagrams

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly

Description and Operation

Manual HVAC Description and Operation HVAC - Manual

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B1 A/C refrigerant pressure sensor. It may take up to 2 minutes for all vehicle systems to power down.

2. Test for less than 10 ohms between the low reference circuit terminal 1 and ground.

If 10 ohms or greater

1. Ignition OFF, disconnect the harness connector at the K20 ECM.

2. Test for less than 2 ohms in the low reference circuit end to end.

If 2 ohms or greater, repair the open/high resistance in the circuit.

If less than 2 ohms, replace the K20 ECM.

If less than 10 ohms

3. Ignition ON.

4. Test for 4.8-5.2 V between the 5 V reference circuit terminal 2 and ground.

If less than 4.8 V

1. Ignition OFF, disconnect the harness connector at the K20 ECM control module.

2. Test for infinite resistance between the 5 V reference circuit and ground.

If less than infinite resistance, repair the short to ground on the circuit.

If infinite resistance

3. Test for less than 2 ohms in the 5 V reference circuit end to end.

If 2 ohms or greater, repair the open/high resistance in the circuit.

If less than 2 ohms, replace the K20 ECM.

If greater than 5.2 V

1. Ignition OFF, disconnect the harness connector at the K20 ECM control module, ignition ON.

2. Test for less than 1 V between the 5 V reference circuit and ground.

If 1 V or greater, repair the short to voltage on the circuit.

If less than 1 V, replace the K20 ECM.

If between 4.8-5.2 V

5. Verify the scan tool A/C High Side Presure Sensor parameter is less than 4.8-5.2 V.

If 4.8-5.2 V or greater

1. Ignition OFF, disconnect the harness connector at the K20 ECM, ignition ON.

2. Test for less than 1 V between the signal circuit terminal 3 and ground.

If 1 V or greater, repair the short to voltage on the circuit.

If less than 1 V, replace the K20 ECM.

If less than 4.8-5.2 V

6. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 2.

7. Verify the scan tool A/C High Side Pressure Sensor parameter is greater than.02 V.

If.02 V or less

1. Ignition OFF, disconnect the harness connector at the K20 ECM.

2. Test for infinite resistance between the signal circuit terminal 3 and ground.

If less than infinite resistance, repair the short to ground on the circuit.

If infinite resistance

3. Test for less than 2 ohms in the signal circuit end to end.

If 2 ohms or greater, repair the open/high resistance in the circuit.

If less than 2 ohms, replace the K20 ECM.

If greater than.02 V

8. Test or replace the B1 A/C refrigerant pressure sensor.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* HVAC Component Replacement Reference Removal and Replacement

* Control Module References Control Module References for engine control module (ECM) replacement, programming, and setup