Engine Oil Pressure Gage Inaccurate or Inoperative
Engine Oil Pressure Gage Inaccurate or Inoperative
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
Circuit/System Description
The engine oil pressure (EOP) sensor changes voltage based on the engine oil pressure. The EOP sensor is a 3-wire sensor comprising of the signal circuit, the low reference circuit and the 5-volt reference circuit. The engine control module (ECM) or the powertrain control module (PCM) supplies 5 volts to the EOP sensor via the 5-volt reference circuit and provides ground via the EOP low reference circuit. The ECM/PCM monitors the signal circuit of the EOP sensor to determine the engine oil pressure sensor voltage is within the normal operating range of approximately 1-4 volts. When the engine oil pressure is high, the EOP sensor voltage is high and the ECM/PCM senses a high signal voltage. When the engine oil pressure is low, the EOP sensor voltage is low and the ECM/PCM senses a low signal voltage. The ECM/PCM sends the EOP information to the instrument panel cluster (IPC) via the serial data circuit.
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 Description and Operation)
* Instrument Cluster Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning)
Circuit/System Testing
Ignition ON, scan tool installed, perform the IPC Gage Sweep Test in the IPC Output Controls. Verify that the EOP gage dials move from minimum to the maximum value and back to the EOP gage minimum value.
If the EOP gage does not perform the IPC Gage Sweep Test, replace the IPC.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Engine Oil Pressure Sensor and/or Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for ECM replacement, setup and programming