P0198
Fix within 1-2 weeksYour engine's computer is getting a signal from the engine oil temperature sensor that is too high, indicating an issue with the sensor or its circuit.
Code P0198 means your engine oil temperature sensor circuit has a high input. Common causes: Faulty EOT sensor (80%), wiring issues (15%). Drivability: Yes, safe to drive, but fix within 1-2 weeks. Repair cost: $50-$150 DIY, $150-$350 professional.
Can I Drive With P0198?
Yes, safe to drive
No restrictions, but fix within 1-2 weeks to avoid long-term issues.
Stop driving immediately if: Flashing CEL, engine overheating, significant power loss, or loud engine noises.
Symptoms of P0198
- 1Check Engine Light is on
- 2Engine cooling fan runs constantly
- 3Poor fuel economy
- 4Engine runs rough or idles poorly
- 5Erratic or incorrect oil temperature gauge reading (if equipped)
Common Causes of P0198
Parts most likely causing this code, ranked by probability
The sensor itself has failed internally, sending an incorrect high voltage signal to the engine computer.
80% of P0198 cases are fixed by replacing this part
A damaged wire, corroded connector, or open circuit in the EOT sensor's wiring causes a high voltage reading.
15% of P0198 cases are fixed by repairing the wiring
The engine computer's internal circuit for the EOT sensor has failed, misinterpreting the sensor's signal.
5% of P0198 cases are fixed by replacing the ECM/PCM
Check These First (Before Buying Parts)
- Visually inspect the EOT sensor's electrical connector for corrosion, bent pins, or loose connections.
- Check the wiring harness leading to the EOT sensor for any signs of fraying, cuts, or damage.
How to Diagnose P0198
- 1Visually inspect the EOT sensor and its wiring harness for any obvious damage, corrosion, or loose connections.
- 2Using a multimeter, test the EOT sensor's resistance at different engine temperatures (if possible) and compare to factory specifications.
- 3Check for proper voltage reference and ground at the EOT sensor connector using a multimeter.
- 4If the sensor and wiring test good, use a scan tool to monitor the EOT sensor's live data to confirm erratic readings.
- 5If all other components check out, consider a faulty ECM/PCM, though this is rare.
P0198 on Popular Vehicles
Toyota Camry
2007-2024On many Camry models, the EOT sensor is located near the oil filter or in the oil pan. It is generally accessible, but ensure you have the correct socket size for removal.
85% fixed by replacing the EOT sensor
Honda Accord
2003-2024Honda Accords often have the EOT sensor integrated into the oil pressure switch or located in the oil pan. Check for oil leaks around the sensor as a potential indicator of a problem.
80% fixed by replacing the EOT sensor
Ford F-150
2004-2024On Ford F-150 trucks, the EOT sensor can be located in various spots depending on the engine (e.g., oil filter adapter, oil pan). Access can be challenging on some V8 and EcoBoost engines, requiring specific tools for removal.
75% fixed by replacing the EOT sensor
Frequently Asked Questions
What does P0198 mean?
P0198 indicates that your vehicle's engine computer is receiving a signal from the engine oil temperature sensor that is too high, suggesting an open circuit or a sensor failure.
Can I drive with P0198?
Yes, you can drive safely with P0198. The engine computer will likely use a default temperature value, which can affect fuel economy and emissions. Fix this within 1-2 weeks to prevent further issues.
Will P0198 clear itself?
No, P0198 will not clear itself. The underlying issue, whether it's a faulty sensor or wiring, must be repaired. After the repair, you can clear the code with a scan tool, or it will clear after several drive cycles if the problem is resolved.
How do I fix P0198 myself?
Start by inspecting the EOT sensor and its wiring for damage. If the wiring looks good, replace the engine oil temperature sensor. This often involves draining some oil or removing the oil filter, depending on the sensor's location.
How much does it cost to fix P0198?
A DIY fix for P0198 typically costs $50-$150 for the sensor and basic tools. Professional repair at a shop ranges from $150-$350, covering parts and labor.
P0198 keeps coming back - why?
If P0198 keeps returning, the initial diagnosis was incomplete. You likely have a persistent wiring issue, a faulty connector, or, in rare cases, a problem with the engine computer itself. Double-check all connections and wiring integrity.
Will P0198 fail emissions/smog test?
Yes, P0198 will cause your vehicle to fail an emissions or smog test. The Check Engine Light being on is an automatic failure in most jurisdictions, and the incorrect oil temperature reading can affect engine performance and emissions output.
What's the difference between P0198 and P0197?
P0198 indicates a high input from the engine oil temperature sensor, meaning the computer sees a very low temperature or an open circuit. P0197 indicates a low input, meaning the computer sees a very high temperature or a short circuit.
P0198 on Ford F-150?
On many Ford F-150 models, the EOT sensor is located near the oil filter housing or in the oil pan. Access can be tight, especially on V8 or EcoBoost engines. Check for oil leaks around the sensor, as this can sometimes indicate a sensor or seal issue.
Questions to Ask Your Mechanic
Did you test the EOT sensor's resistance at different temperatures?
Good answer: Yes, I monitored the live data and checked the resistance with a multimeter. It showed an open circuit or extremely high resistance, confirming the sensor is faulty.
What did you find when checking the wiring for the EOT sensor?
Good answer: I performed a continuity test and checked for shorts to power or ground. The wiring harness is intact, and the connectors are clean and secure.
Repair Cost Estimate
DIY Repair
Parts only
$50-$150
Shop Repair
Parts + labor
$150-$350
Save $100-$200 by doing it yourself
Difficulty
intermediate
Time
1-2 hours
Intermediate - requires basic hand tools, a multimeter, and potentially an OBD-II scan tool for diagnosis and clearing the code.
Cost of Waiting
Ignoring P0198 can lead to your engine running with an incorrect fuel mixture and ignition timing, potentially causing reduced fuel economy, increased emissions, and in some cases, the cooling fan running constantly, which wears out the fan motor. A $50 sensor fix now prevents these ongoing issues.
While You're In There...
If the EOT sensor is located in the oil pan or requires draining oil for access, it is a good time to perform an oil change.
If you are changing the engine oil, replacing the oil filter is a standard part of that maintenance.
Tools You'll Need
- OBD-II Scan Tool
- Multimeter
- Socket wrench set
- EOT sensor socket (specific size may vary)
- Drain pan (if draining oil is necessary)
- Torque wrench
P0198 is a common sensor code. Most repairs involve replacing an affordable sensor, and your engine will return to normal operation afterward.
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Your Next Steps
Step 1: Inspect the EOT sensor's wiring and connector for any visible damage or corrosion. Clean any corrosion and ensure connections are tight.
Step 2: If the wiring looks good, use a multimeter to test the EOT sensor's resistance. Compare your readings to the factory specifications for your vehicle. If the sensor shows an open circuit or extremely high resistance, replace it.
Step 3: Parts you'll likely need: A new Engine Oil Temperature Sensor.