Engine Oil Pressure Indicator Always On
Engine Oil Pressure Indicator Always On (4.8L, 5.3L, 6.0L, 6.2L, and 7.0L)
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.
Diagnostic Fault Information
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) supplies 5-volts to the EOP sensor via the 5-volt reference circuit and provides ground via the EOP low reference circuit. The ECM 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 senses a high signal voltage. When the engine oil pressure is low, the EOP sensor voltage is low and the ECM senses a low signal voltage. The ECM sends the EOP information to the instrument panel cluster (IPC) via the serial data circuit. The IPC illuminates the engine oil pressure indicator when it receives a serial data message indicating a low engine oil pressure condition.
Reference Information
Schematic Reference
* Instrument Cluster Schematics (Instrument Cluster Diagrams)
* Engine Controls Schematics (Electrical Diagrams)for the 4.8L, 5.3L, 6.0L, 6.2L and 7.0L engines
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
* Instrument Cluster Description and Operation (Description and Operation)
* Engine Control Module Description (Engine Control Module Description)for the 4.8L, 5.3L, 6.0L, 6.2L and 7.0L engines
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)for Scan Tool Information
Circuit/System Testing
Ignition ON, scan tool installed, perform the Displays Test in the IPC Output Controls Special Functions . Verify that the engine oil pressure (EOP) indicator turns off after the Displays Test.
If the EOP indicator does not turn off after the Displays Test, test or 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)for the 4.8L, 5.3L, 6.0L, 6.2L and 7.0L engines
* Control Module References (Programming and Relearning)for IPC replacement, setup and programming