OBD-II Generic Error Code P0198: How to Fix It – Engine Oil Temp Sensor High

Medium 1-2 hours Medium Severity Verified June 2026
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Error Code
P0198
Brand
OBD-II Generic
Product Type
automotive
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
1-2 hours
Error code P0198 indicates that your vehicle's Engine Control Module (ECM) has detected a high voltage signal from the engine oil temperature (EOT) sensor, meaning the sensor is reading an abnormally high temperature or there's an electrical problem. This can cause poor engine performance, increased emissions, and potential damage if ignored.
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Tools You'll Need

How to Fix Error Code P0198

  1. Check for Engine Oil Level and Condition

    Always work on a cool engine to avoid burns from hot oil or components.

  2. Inspect the Oil Temperature Sensor and Connector

  3. Test the Sensor Resistance

    Ensure the ignition is off and the connector is disconnected before testing.

  4. Check the Wiring and Voltage at the ECM

    Use caution when probing wires; avoid shorting pins.

  5. Replace the Oil Temperature Sensor

    Some oil may spill – have a drain pan ready. Dispose of rags properly.

  6. Clear the Code and Test Drive

    If the code returns immediately, further diagnosis is needed – possibly an ECM issue.

Parts You May Need

Engine Oil Temperature Sensor
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Engine Oil
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Engine Oil Temperature Sensor
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Engine Oil
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Engine Oil Temperature Sensor
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Engine Oil
Check Price on Amazon
Engine Oil Temperature Sensor
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Engine Oil
Check Price on Amazon
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When to Call a Professional

If you have tested the sensor, wiring, and voltage but the code persists, or if you are uncomfortable working with electrical systems, consult a professional mechanic. An ECM failure or complex wiring issue may require specialized diagnostic equipment.

Frequently Asked Questions

Can I drive with a P0198 code?
It is not recommended to drive long distances with this code, as it can cause poor fuel economy, engine damage, or stalling. Have it diagnosed promptly.
What causes P0198?
Common causes include a faulty engine oil temperature sensor, wiring issues (shorts/opens), low oil level, a stuck thermostat, or rarely an ECM problem.
How much does it cost to fix P0198?
DIY cost: $20-$80 for a new sensor. Mechanic cost: $150-$300 including labor and parts.
Will clearing the code fix the problem?
Clearing the code only removes it temporarily. If the underlying issue (e.g., faulty sensor) isn't fixed, the code will return.
Where is the oil temperature sensor located?
It is usually located near the oil filter, on the engine block, or in the oil pan. Consult your vehicle's service manual.

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