P0198: Engine Oil Temperature Sensor Circuit High
Key takeaways
- P0198 means the engine oil temperature sensor's signal voltage is above its normal range, which on most cars points to an open circuit: an unplugged connector, a broken wire or a failed sensor.
- Before blaming the sensor, check that the engine isn't really hot: the temperature gauge should read normal and the oil level should be on the dipstick.
- With a normal gauge and a full oil level, it's safe to drive while you get it fixed; the engine doesn't depend on this reading to run.
- An oil temperature sensor costs about $80–$250 at a US independent shop, and a connector repair $100–$250.
- Volkswagen has bulletins for a yellow oil warning light with P0196 or P0198 on 2016–2019 models, and Jeep has one for P0198 on the 2021 Grand Cherokee.
What P0198 means
The sensor that reports your engine oil temperature is sending a signal above the range the computer accepts. Scanners call it “Engine Oil Temperature Sensor Circuit High,” and older tools say “Engine Oil Temperature Sensor High Input.” The sensor is a thermistor in the oil pan, filter housing or block. The computer sends it a reference voltage and reads what comes back. On most cars, a signal stuck near the top of that range means the circuit is open, and the computer sees oil far colder than the engine could be. So on most cars P0198 is a wiring or sensor fault, not a report of hot oil. Some cars use the reading to protect the engine, so the code still deserves a quick real-world check.
Is it safe to drive?
Yes, in most cases, once you’ve checked two things. First, the temperature gauge should sit where it normally does. Second, the oil level should be on the dipstick between the marks. If both are normal and no red oil light is on, the engine isn’t actually hot and you can drive while you get the circuit fixed. Some cars limit rpm or turn on a yellow oil light while the code is set.
What changes the answer: a gauge climbing toward hot, a red oil pressure light, low oil, or a new knocking noise. Then it may not be the sensor at all. Pull over, shut the engine off and check the oil and coolant. See car overheating if the gauge is high.
Causes, ranked
| Cause | How you confirm it | Typical cost (US independent shop, 2026) |
|---|---|---|
| Connector loose, corroded or oil-soaked | Unplug it and look; reading changes when the plug is wiggled | $0 DIY reseat; $100–$250 repair |
| Failed oil temperature sensor (open inside) | Resistance out of spec against a temperature chart; jumper test at the plug brings the reading back | $80–$250 |
| Broken or chafed wire in the engine harness | Sensor tests good, signal still high; look near the oil pan and exhaust | $100–$250 splice; $250–$600 harness section |
| Combined oil level/temperature sensor (some makes) | Yellow oil light with the code; same test on the combined sensor | $80–$250 |
| Engine software (rare) | Dealer finds a bulletin for your model | $100–$200, often $0 under warranty |
What to check first
- Check the gauge and the oil level. Confirm the engine isn’t really hot and the oil isn’t low before you treat this as a sensor code. A top-up costs little; ignoring real low oil can cost an engine.
- Read the oil temperature in live data. A reading far below outside temperature, often around -40°F, on a warm engine confirms an open circuit.
- Find the sensor and check the connector. On many engines it sits on the oil pan or filter housing, where road grime and oil leaks get into the plug.
- Test the circuit before buying a sensor. A shop can jumper the connector to see whether the reading changes, which separates sensor from wiring.
- Clear the code and drive after a connector repair; if the plug was the problem, it stays gone.
The bulletins are few. Volkswagen has nine listing a yellow oil warning light with P0196 or P0198 on 2016–2019 models including the Tiguan, Passat, Jetta, GTI, Golf and Atlas. Jeep has two naming P0198 on the 2021 Grand Cherokee.
What it costs
The cheap outcome is a reseated or cleaned connector. The common outcome is a new oil temperature sensor at $80–$250, or a wiring repair at $100–$250. The expensive outcome is a section of engine harness at $250–$600. A $100–$180 diagnosis that tests the circuit first keeps you from buying a sensor when a wire is broken. If an oil leak soaked the connector, fix the leak too, or the code will return; see car leaking oil.
Related codes
P0196 and P0197 are the range/performance and low codes for the same sensor. If the oil pressure circuit is also flagged, you’ll see P0520 or P0521; those matter more, because they can mean low oil pressure. A coolant sensor fault like P0117 can make the gauge read wrong at the same time.
What owners report to NHTSA
1 complaints filed with NHTSA mention P0198, 1 of them since 2015, across 1 different models. The component owners most often filed it under: power train.
Manufacturer service bulletins that name P0198
11 technical service bulletins and manufacturer communications filed with NHTSA mention P0198, from 2 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:
- JEEP GRAND CHEROKEE (2021), bulletin 10188747: MIL Malfunction Indicator Lamp On, DTC P0198 Oil Temperature Sensor Circuit High
- VOLKSWAGEN TIGUAN (2016, 2017, 2018, 2019), bulletin 10149871: Water leaks from the sunroof/overhead light console area, sunshade is to blinding, MIL-on P0441 in the ECM, coolant leak at the coolant pump, Yellow oil warning light on with any of the following faults P0196 P0198 B1041…
- VOLKSWAGEN GTI (2016, 2017, 2018, 2019), bulletin 10149877: Water leaks from the sunroof/overhead light console area, Park distance to sensitive to control, coolant leak at the coolant pump, Yellow oil warning light on with any of the following faults P0196 P0198 B104129 B104135,…
- VOLKSWAGEN TOUAREG (2017, 2018, 2016), bulletin 10150841: Coolant leak at the coolant pump, Yellow oil warning light on with any of the following faults P0196 P0198 B104129 B104135, Customer states the sunroof is making noise, squeak & rattle, MIL-on with P0300-P0304 in the ECM…
- VOLKSWAGEN ATLAS (2018, 2016, 2017), bulletin 10150840: Coolant leak at the coolant pump, Yellow oil warning light on with any of the following faults P0196 P0198 B104129 B104135, Customer states the sunroof is making noise, squeak & rattle, MIL-on with P0300-P0304 in the ECM…
Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.
Frequently asked questions
Does P0198 mean my engine oil is overheating?
Usually not. On most cars a high signal voltage means an open circuit, which the computer reads as cold oil, not hot. But don't assume: check that the temperature gauge reads normal and the oil level is full. If the gauge is high or the oil is low, treat it as a real problem first.
Can I drive with P0198?
Yes, if the gauge reads normal, the oil level is full and no red oil light is on. The engine doesn't need this sensor to run. A red oil pressure light, a gauge in the red or a new knocking noise means stop and shut it off.
Can low oil cause P0198?
Not directly; it's an electrical code. But on some engines the oil temperature sensor shares a housing with the oil level sensor, and very low oil can also make the engine run hotter. Checking the dipstick takes a minute and rules it out.
Why is my yellow oil light on with P0198?
On many Volkswagen engines the oil temperature and oil level readings come from the same sensor, so a fault in that circuit can turn on the yellow oil warning. Volkswagen has bulletins listing exactly that on 2016–2019 models. Check the level first, then the sensor and its connector.