P0520

Engine Oil Pressure Indicator Malfunction - DTC P0520

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.

Diagnostic Fault Information






Circuit/System Description

The engine oil pressure switch is a normally closed switch that opens with the proper oil pressure. With the ignition switch turned ON and the engine not running, the engine control module (ECM) should detect a low signal voltage input. With the engine running, the engine oil pressure switch opens and the ECM should detect a high signal voltage input. When the oil pressure is low, the ECM sends a message via serial data to the body control module (BCM). The BCM then sends a message via serial data to the instrument cluster requesting the engine oil pressure indicator turned ON.

Reference Information

Schematic Reference

Instrument Cluster Schematics Instrument Cluster Schematics

Connector End View Reference

Component Connector End Views Sunshade - Left (DH6)

Description and Operation

Indicator/Warning Message Description and Operation Indicator/Warning Message

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 Verification

Ignition ON, observe the scan tool Engine Oil Pressure Switch parameter with the ignition switch turned ON and the engine not running the reading should be Low, with the engine running the reading should be OK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the B37 engine oil pressure switch.

2. Ignition ON, verify the scan tool Engine Oil Pressure Switch parameter is OK.

• If not the specified value, test for the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the K20 engine control module.

3. Install a 3 A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool Engine Oil Pressure Switch parameter is Low.

• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.

4. Command the All Indicators test ON and OFF with the scan tool. The engine oil pressure indicator should turn ON and OFF when changing between the commanded states.

• If the engine oil pressure indicator always on or always off, replace the P16 instrument cluster.

5. If all circuits test normal, test or replace the B37 engine oil pressure switch.

Repair Instructions

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

* Engine Oil Pressure Switch Replacement Service and Repair

* Control Module References Control Module References for instrument cluster or ECM replacement, programming and setup