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.
Diagnostic Fault Information
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 High Speed CAN-Bus to the body control module (BCM). The BCM then sends a message via Low Speed CAN-Bus to the instrument cluster requesting the engine oil pressure indicator turned ON.
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
Ignition ON, observe the scan tool Engine Oil Pressure Switch parameter with the ignition switch turned ON and the engine not running the reading should be Low, with the engine running the reading should be OK.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the B37 Engine Oil Pressure Switch.
2. If applicable, test for less than 30 ohm between the low reference circuit terminal B and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
3. Ignition ON, verify the scan tool Engine Oil Pressure Switch parameter is OK.
• If not the specified value, test for the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.
4. Install a 3 A 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 K20 Engine Control Module.
5. Command the All Indicators test ON and OFF with the scan tool. The engine oil pressure indicator should turn ON and OFF when changing between the commanded states.
• If the engine oil pressure indicator always on or always off, replace the P16 Instrument Cluster
6. If all circuits test normal, test or replace the B37 Engine Oil Pressure Switch.
Component Testing
Static Test
1. Ignition OFF, disconnect the harness connector at the B37 Engine Oil Pressure Switch.
2. Test for infinite resistance between the signal terminal A and the low reference terminal B with the switch in the open position.
• If not the specified value, replace the B37 Engine Oil Pressure Switch.
3. Test for less than 5 ohm between the signal terminal A and the low reference terminal B with the switch in the closed position.
• If greater than the specified range, replace the B37 Engine Oil Pressure Switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Engine Oil Pressure Sensor and/or Switch Replacement (LF1) (Service and Repair)
* Control Module References (Programming and Relearning)for instrument cluster or ECM replacement, setup, and programming