Oil Level Sensor: Testing and Inspection

Engine Oil Level Sensor Diagnosis

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





Typical Scan Tool Data





Circuit/System Description

The powertrain control module (PCM) monitors the state of the engine oil level switch. The PCM uses this information to determine when the engine oil level is low before the engine is running, and then notify the driver of the condition.

When the ignition is ON, the PCM supplies 5 volts to the engine oil level signal circuit. The engine oil level switch is normally closed to ground, and the signal circuit voltage is low. The engine oil level switch is open when the engine oil level is low. The PCM will request the driver information center (DIC) to display the ENGINE OIL LOW, ADD OIL warning message when the following conditions exist:

* The ignition is ON and the PCM detects voltage on the engine oil level circuit
* The ignition is turned OFF
* More than 30 minutes has passed
* The engine is running
* The PCM continues to detect signal voltage at the engine oil level signal circuit

The PCM will requests the DIC to discontinue the ENGINE OIL LOW< ADD OIL message if the following conditions exist:

* The ignition is OFF for more than 15 seconds
* The engine oil level is increased sufficiently to close the switch
* The engine is running

Reference Information
Schematic Reference

Engine Mechanical Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
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 Verification

1. Verify the proper engine oil level.
2. Ignition ON, observe the scan tool Engine Oil Level Switch parameter. The reading should be OK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the engine oil level switch.
2. Test for less than 2 ohms between the ground circuit terminal B and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Engine Oil Level Switch parameter is low.

• If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the PCM.

4. Install a 3A fused jumper wire between the signal circuit terminal A and the ground circuit terminal B. Verify the scan tool Engine Oil Level Switch parameter is OK.

• 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 PCM.

5. If all circuits test normal, test or replace the PCM.

Component Testing

1. Ignition OFF, disconnect the harness connector at the engine oil level switch.
2. Test for less than 2 ohms between the signal terminal A and the ground terminal B.

• If greater than the specified range, replace the engine oil level switch.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Engine Oil Level Sensor and/or Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for PCM replacement, setup, and programming