Engine Oil Pressure Indicator Malfunction

Engine Oil Pressure Indicator Malfunction (2.2L and 2.4L)

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 Instructionsprovide an overview of each diagnostic category.

Diagnostic Fault Information






Circuit/System Description

The engine oil pressure (EOP) 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 pressure switch opens, and the ECM should detect a high signal voltage input. When the oil pressure is low, the ECM sends a serial data message to the body control module (BCM) requesting the EOP indicator turned ON. The instrument panel cluster (IPC) illuminates the EOP indicator when the IPC receives a serial data message from the BCM requesting the EOP indicator turned ON.

Reference Information
Schematic Reference

Instrument Cluster Schematics Instrument Cluster Schematics
Connector End View Reference

Component Connector End Views Connector End Views By Name
Description and Operation

* Instrument Cluster Description and Operation Description and Operation
* Indicator/Warning Message Description and Operation (Radio) Indicator/Warning Message (Radio)

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 Programming and Relearningfor scan tool information

Circuit/System Verification

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

If not the specified value, refer to:

* Oil Pressure Diagnosis and Testing Oil Pressure Diagnosis and Testingfor the 2.4L engine

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the engine oil pressure (EOP) switch.
2. Ignition OFF, test for less than 1 ohm between the low reference circuit terminal B and ground (LY7 only).

• If greater than the specified value, test the circuit for an open/high resistance.

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

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

4. Ignition ON, install a 3-amp 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 ECM.

5. Ignition ON, command the EOP indicator OFF with the scan tool.

• If the EOP indicator does not turn OFF, replace the IPC.

6. If all circuits test normal, test or replace the 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 Repairfor the 2.2L or 2.4L engine
* Control Module References Programming and Relearningfor the ECM replacement, setup, and programming