Chevrolet Trax: DTC P0521: Engine oil pressure sensor performance malfunction

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 Descriptor

DTC P0521

Engine Oil Pressure Sensor Performance Malfunction

Diagnostic Fault Information

Typical Scan Tool Data

ECM - Engine Oil Pressure Switch

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.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

• The ECM detects that the engine oil pressure switch signal circuit is pulled low.
• The engine oil pressure is outside of a calculated working range determined by engine speed and temperature.
• The above condition is present for greater than 10 seconds.

Action Taken When the DTC Sets

The Instrument Cluster illuminates the service vehicle soon indicator and the oil pressure low indicator.

Conditions for Clearing the DTC

The DTC becomes history when the conditions for setting the DTC are no longer present.

Diagnostic Aids

DTC P0521 can set if engine oil pressure is outside the calculated engine oil pressure model stored in the engine control module. This can be an indication of mechanical engine issues causing lower than expected engine oil pressure.

Reference Information

Schematic Reference

Instrument Cluster Schematics (Encore), Instrument Cluster Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

• Instrument Cluster Description and Operation
• Indicator/Warning Message Description and Operation
• Driver Information Center (DIC) Description and Operation (base Instrument Cluster), Driver Information Center (DIC) Description and Operation (uplevel Instrument Cluster)

Electrical Information Reference

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

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (LUV) , Powertrain Diagnostic Trouble Code (DTC) Type Definitions (2H0)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.
2. Verify the scan tool Engine Oil Pressure parameter is Low.

• If not Low

Refer to Circuit/System Testing.

• If Low

3. Engine running.
4. Verify the scan tool Engine Oil Pressure parameter is OK.

• If not OK

Refer to Circuit/System Testing.

• If OK

5. All OK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the B37 Engine Oil Pressure Switch, ignition ON.
2. Verify the scan tool Engine Oil Pressure Switch parameter is OK.

If not OK

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the signal circuit terminal 1 (or A) and ground.

• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K20 Engine Control Module.
• If OK

3. Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground.
4. Verify the scan tool Engine Oil Pressure Switch parameter is Low.

If not Low

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.

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

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 Engine Control Module.
• If Low

5. Test or replace the B37 Engine Oil Pressure Switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Displays and Gauges Component Replacement Reference
• Control Module References for ECM replacement, programming and setup

DISPLAYS AND GAUGES COMPONENT REPLACEMENT REFERENCE

Displays and Gauges Component Replacement Reference

SYMPTOMS - DISPLAYS AND GAUGES

NOTE: The following steps must be completed before using the symptom diagnostic tables.

1. Before using the symptom diagnostic tables, perform the Diagnostic System Check - Vehicle
2. Review the system operation in order to understand the system functions. Refer to the following description and operations:

• Instrument Cluster Description and Operation
• Indicator/Warning Message Description and Operation
• Driver Information Center (DIC) Description and Operation (base Instrument Cluster),
• Driver Information Center (DIC) Description and Operation (uplevel Instrument Cluster)
• Audible Warnings Description and Operation

Visual/Physical Inspection

• Inspect for aftermarket devices which can affect the operation of the instrument panel cluster or the audible warning systems. Refer to Checking Aftermarket Accessories
• Inspect the accessible system components or the visible system components for obvious damage or for obvious conditions which can cause the symptom.
• Inspect for the proper fluid levels.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

Gauges and Odometer

• Instrument Cluster Gauges Malfunction (Encore only)
• Fuel Gauge Malfunction
• Speedometer and/or Odometer Malfunction (Encore only)

Indicators

• Charge Indicator Malfunction
• Engine Oil Pressure Indicator Malfunction

Driver Information Center

• Driver Information Center Switch Malfunction
• Outside Air Temperature Display Malfunction

Audible Warnings

Chime Malfunction

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