Engine Oil Pressure Indicator Malfunction

Engine Oil Pressure Indicator Malfunction

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.

Circuit/System Description

The engine oil pressure sensor changes voltage based on the engine oil pressure. The engine oil pressure sensor is a 3-wire sensor comprised of the signal circuit, the low reference circuit and the 5-V reference circuit. The engine control module (ECM) supplies 5 V to the engine oil pressure sensor via the 5-V reference circuit and provides ground via the engine oil pressure sensor low reference circuit. The ECM monitors the signal circuit of the engine oil pressure sensor to determine the engine oil pressure sensor voltage is within the normal operating range of approximately 1-4 V. When the engine oil pressure is high, the engine oil pressure sensor voltage is high and the sensor senses a high signal voltage. When the engine oil pressure is low, the engine oil pressure sensor voltage is low and the ECM senses a low signal voltage. The ECM sends the engine oil pressure sensor information via High Speed CAN-Bus to the body control module (BCM). The BCM then sends the engine oil pressure sensor information via Low Speed CAN-Bus to the instrument cluster.

Reference Information
Schematic Reference

Instrument Cluster Schematics (Instrument Cluster Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
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 (Programming and Relearning) for scan tool information

Circuit/System Verification

1. Ignition ON, command the All Indicators test ON and OFF with the scan tool, verify that the engine oil pressure indicator changes between turn ON and OFF.

• If the engine oil pressure indicator always stays ON or always OFF, replace the P16 Instrument Cluster.

2. If the engine oil pressure indicator changes between ON and OFF, replace the K20 Engine Control Module.

Repair Instructions

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

Control Module References (Programming and Relearning) for instrument cluster or ECM replacement, setup, and programming.