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 serial data to the body control module (BCM). The BCM then sends a message via serial data to the instrument cluster requesting the engine oil pressure indicator turned ON.
Diagnostic Aids
Low engine oil pressure will also cause this DTC to set. If low engine oil pressure is suspected, refer to Oil Pressure Diagnosis and Testing Testing and Inspection.
Reference Information
Schematic Reference
Instrument Cluster Schematics Instrument Cluster Schematics
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
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 Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Verify the engine oil pressure indicator turns on & off when commanding the All Indicators ON and OFF with a scan tool.
• If the engine oil pressure Indicator does not turn on and off.
Replace the P16 instrument cluster.
• If the engine oil pressure Indicator turns on and off
3. Verify the scan tool Engine Oil Pressure Switch parameter is Low.
• If not Low
Refer to Circuit/System Testing.
• If Low
4. Engine running.
5. Verify the scan tool Engine Oil Pressure Switch parameter is OK.
• If not OK
Refer to Circuit/System Testing.
• If OK
6. All OK.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the B37 engine oil pressure switch, ignition ON.
2. Verify the scan tool Engine Oil Pressure Switch parameter is OK.
• If not OK
1. Ignition OFF, disconnect the harness connector at the K20 engine control module.
2. Test for infinite resistance between the signal circuit terminal 1 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K20 engine control module.
• If OK
3. Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground.
4. Verify the scan tool Engine Oil Pressure Switch parameter is Low.
• If not Low
1. Ignition OFF, disconnect the harness connector at the K20 engine control module, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 engine control module.
• If Low
5. Test or replace the B37 engine oil pressure switch.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Engine Oil Pressure Indicator Switch Replacement Service and Repair for the 1.8L engine
* Control Module References Control Module References for instrument cluster or ECM replacement, programming and setup