Diagnostic trouble code P0198 — what it means, the common
causes, and how to confirm the real fault before replacing parts.
What does P0198 mean?
P0198 indicates: Engine Oil Temperature Sensor High.
This relates to the Fuel & air metering system.
Common causes of P0198
NTC thermistor (Oil Temperature Sensor G8) fault in main oil gallery
electrical fault in oil temperature sensor circuit causing high signal
What to check (live data)
oil temperature sensor signal (NTC thermistor output); piston cooling jets activate at oil temperatures over 248°F (120°C)
Parts often involved in P0198
Oil Temperature Sensor G8
Don't replace parts until the root cause is confirmed — many of these codes are caused by wiring, a connector or an upstream fault, not the part itself.
Get the confirmed root cause for P0198 — on YOUR vehicle
A code is a symptom, not a diagnosis. AutoDX Pro cross-checks several
independent assessments, pinpoints the actual root cause, gives you the
exact tests to confirm it, and shows the parts — only after the cause is
confirmed. Reads your scan-tool photo and decodes your VIN with open
recalls.
P0198 is a diagnostic trouble code: Engine Oil Temperature Sensor High.
What are the common causes of P0198?
Common causes include: NTC thermistor (Oil Temperature Sensor G8) fault in main oil gallery, electrical fault in oil temperature sensor circuit causing high signal. The exact cause depends on the vehicle — confirm it before replacing parts.
Can I keep driving with P0198?
It depends on the fault and your symptoms. Some causes are minor, others can damage components or affect safety. Get the root cause confirmed before deciding.
How do I fix P0198?
Confirm the actual root cause with targeted tests first, then replace only the part that's at fault. AutoDX Pro gives you the root cause, the exact tests, and the parts for P0198 on your specific vehicle.