P0198 — Engine Oil Temperature Sensor Low
Drive with caution — fix soon.
What P0198 means
This code means the oil temperature sensor's voltage signal is lower than the normal operating range, which usually points to a short circuit to ground, a damaged wire, or a failed sensor. The most common fix is repairing the wiring or replacing the sensor. It's a common, well-understood code that's typically affordable to fix.
Common symptoms
- Check engine light is on
- Oil temperature reads abnormally low or pinned
- Harsh or erratic transmission shifting
- Slight decrease in fuel economy
- Occasional rough idle or hesitation
Common causes
- Short to ground in the sensor circuit
- Failed engine oil temperature sensor
- Corroded or damaged sensor connector
- Damaged or pinched wiring harness
- Faulty engine control module (rare)
Typical repair cost
$100 – $300
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0198 code?
Usually yes, since the engine typically still runs. However, the faulty oil temperature signal can affect shifting and engine protection, so it's best to get it checked soon.
How much does it cost to fix a P0198 code?
Most repairs cost between $100 and $300. Fixing a shorted wire or connector is cheaper, while replacing the oil temperature sensor with labor lands toward the higher end.
Is a P0198 code serious?
It's moderate. The car will usually drive, but because the computer relies on accurate oil temperature for engine protection, it shouldn't be ignored long-term.
What does 'sensor low' mean in plain terms?
It means the sensor's electrical signal dropped below the normal range, as if the oil were impossibly cold. This usually points to a wiring short to ground or a failed sensor rather than a real temperature problem.