Engine Oil Level Sensor Diagnosis

Engine Oil Level Sensor Diagnosis

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






Typical Scan Tool Data






Circuit/System Description

The engine oil level sensor/switch is a normally-closed with proper engine oil level. The switch opens when the engine oil level drops below a calibrated level. The engine control module (ECM) monitors the engine oil level signal circuit when the ignition is ON, and the engine is OFF. With the switch in the closed position, the ECM detects a low voltage signal circuit. With the switch in the open position, the ECM detects a high voltage on the signal circuit. When high voltage is detected on the signal circuit, the ECM will send a serial data message to the instrument panel cluster and a message is displayed on the driver information center.

The following information determines the message sent form the ECM to the instrument cluster. The Engine Oil Level Low message is displayed only after the ECM detects a high voltage on the signal circuit for three consecutive ignition cycles, followed by an ignition OFF event from 15 min to greater than 50 min, depending on the engine oil temperature.

The Engine Oil Level Low message is turned OFF when the ECM detects a low voltage on the signal circuit after an ignition OFF event for greater than 90 s, then followed by the ignition ON for less than 1 s.

Reference Information

Schematic Reference

* Engine Mechanical Schematics [1][2]Diagrams

* Instrument Cluster Schematics Instrument Cluster Schematics

Connector End View Reference

Component Connector End Views Sunshade - Left

Description and Operation

* Instrument Cluster Description and Operation Instrument Cluster

* 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. Verify proper engine oil level.

• If not at proper level
Add oil as necessary.

• If at proper level

2. Ignition ON, verify the scan tool Engine Oil Level parameter reads OK.

• If not OK
Refer to Circuit/System Testing.

• If OK

3. All OK.

Circuit/System Testing

Note: Verify proper engine oil level before continuing with diagnosis.

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B35 Engine Oil Level Switch. It may take up to 2 minutes for all vehicle systems to power down.

2. Test for less than 10 ohms between the low reference circuit terminal 1 and ground

• If 10 ohms or greater

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.

2. Test for less than 2 ohms in the low reference 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 less than 10 ohms

3. Ignition ON.

4. Verify the scan tool Engine Oil Level Switch parameter reads Low.

• If the Engine Oil Level Switch parameter reads OK
Test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.

• If the Engine Oil Level Switch parameter reads Low

Note: If a short to voltage is found on the signal circuit, the fuse in the 3A jumper wire will open.

5. Install a 3A fused jumper wire between the signal circuit terminal 2 and the ground circuit terminal 1.

6. Verify the scan tool Engine Oil Level Switch parameter reads OK.

• If the Engine Oil Level Switch parameter reads Low
Test the signal circuit terminal 2 for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

• If the Engine Oil Level Switch parameter reads OK

7. Test or replace the engine oil level sensor and/or switch.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Engine Oil Level Sensor Replacement Service and Repair

* Control Module References Control Module References for the ECM replacement, programming, and setup