P0198

Engine Oil Temperature Sensor A Circuit High

Engine oil temperature sensor Generic OBD-II Low

What it means

P0198 means the engine oil temperature sensor signal is too high, which corresponds to an implausibly cold reading — usually an open circuit, a short to voltage, or a failed sensor. It's a sensor-signal fault: the ECM substitutes a value, so the engine typically keeps running normally, though temperature-based functions like cooling fans or shift timing may be slightly affected until it's repaired.

Low

Can I keep driving? Usually still drivable — this is a temperature-sensor signal fault; the ECM substitutes a value, so drivability is normally unaffected.

Real-world scan data

Seen in

396

scans in the past year

Found in

0.1%

of scans

0.1%

of scans that found faults

Appears alongside · share of P0198 scans

P0113in 19.7% of scans

P0118in 16.2% of scans

P0335in 13.6% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Often no noticeable driving symptom
Oil temperature reads implausibly low/cold on a scan tool
Possible effect on cooling-fan or shift logic on some vehicles

Common causes

Most likely first

Faulty engine oil temperature sensorLikely
Signal wire open or shorted to voltageCommon
Loose or corroded electrical connectorCommon
Poor sensor groundLess often
Faulty ECM (rare — confirm the sensor and wiring first)Less often

How to diagnose & fix

Work through it in order

Read the live oil-temperature value and compare it to actual engine temperature — a circuit-high fault reads out of range.
Inspect the sensor connector and wiring for an open or a short to voltage.
Check the sensor's ground and reference circuit with the key on.
Back-probe the signal wire to decide whether the sensor or the wiring is at fault.
Replace the engine oil temperature sensor if it reads out of range with good wiring, then clear and re-test.

FAQ

Quick answers

Is it safe to drive with P0198?+

In most cases yes. It's an oil-temperature signal fault and the ECM uses a default value, so the engine still runs normally. Fix it to keep temperature-based logic accurate.

Can I just clear P0198?+

It returns until the sensor or wiring is repaired. Clearing alone only resets the light temporarily.

Read & clear P0198 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX