Engine Oil Temperature Sensor Diagnosis
Engine Oil Temperature 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 and Temperature Sensor is a variable resistor that measures the temperature of the engine oil. The Engine Control Module (ECM) supplies 5 V to the Engine Oil and Temperature Sensor signal circuit and supplies a ground to the low reference circuit.
Reference Information
Schematic Reference
* Engine Mechanical Schematics [1][2]Diagrams
* Instrument Cluster Schematics Instrument Cluster Schematics
Connector End View Reference
Component Connector End Views A/C Compressor Clutch
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. Engine operating.
2. Verify the scan tool Engine Oil Temperature Sensor parameter is between -40 to +150°C (-40 to +302°F) and changes with engine temperature.
• If not between -38 to +148°C (-36 to +298°F) or does not change
Refer to Circuit/System Testing.
• If between -38 to +148°C (-36 to +298°F) and changes
3. All OK.
Circuit/System Testing
Note: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B35C Engine Oil Level and Temperature Sensor. 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 C 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 Temperature Sensor parameter is warmer than 148°C (298°F).
• If 148°C (298°F) or less
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the signal circuit terminal B 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 warmer than 148°C (298°F)
5. Install a 3A fused jumper between the signal circuit terminal B and the low reference circuit terminal C.
6. Verify the scan tool Engine Oil Temperature Sensor parameter is colder than -38°C (-36°F).
• If -38°C (-36°F) or colder
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 1V between the signal circuit and ground.
• If 1V or greater, repair the short to voltage on the circuit.
• If less than 1V
3. Ignition OFF.
4. 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 warmer than -38°C (-36°F)
7. Test or replace the B35C Engine Oil and Temperature Sensor.
Component Testing
1. Ignition OFF, remove the B35C Engine Oil Level and Temperature Sensor.
2. Test the B35C Engine Oil Level and Temperature Sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the Temperature Versus Resistance (Engine Coolant Temperature Sensor) Temperature Versus Resistance - Engine Coolant Temperature Sensor table and verify that the resistance is within 5% of the specification.
• If not within the specified range
Replace the B35C Engine Oil Level and Temperature Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Engine Oil Level Sensor and/or Switch Replacement Service and Repair
* Control Module References Control Module References for the ECM replacement, programming, and setup