P0198 fault code: Engine Oil Temperature Sensor High

P0198 means “Engine Oil Temperature Sensor High” — a fuel and air metering fault in the powertrain.

Can I DIY?

Professional-only boundary. You may read P0198 on a scanner; oil-temperature circuit diagnosis is garage work.

Do not DIYReviewed page boundary
ToolsSpecialist equipment

This is the conservative boundary from the reviewed code record. This page has no frozen site-wide safety grade, so it does not publish a repair route.

What to tell the garage about P0198

Do not drive until checked. The engine computer is reporting an oil-temperature sender reading that is too high for the conditions. That is a circuit or sensor report, not proof the oil is boiling.

Take these reviewed, code-specific details with you. They help the garage confirm the fault without turning this page into a repair procedure.

  • Engine Oil Temperature Sensor High: Registration number
  • Engine Oil Temperature Sensor High: Exact code P0198 and any companion codes
  • Engine Oil Temperature Sensor High: Whether the engine management light is steady or flashing
  • Engine Oil Temperature Sensor High: Whether an oil-temperature or oil-pressure warning also showed
P01xxFuel and air metering
MOT fail riskif the warning light stays on

What does P0198 mean?

P0198 is a generic (SAE standard) powertrain code reported by your car’s engine control unit. It sits in the P01xx block, which covers fuel and air metering. The stored description is “Engine Oil Temperature Sensor High”. The code itself tells you which circuit or system tripped the fault — not always the exact part that failed.

Will P0198 fail an MOT?

A lit engine management light is a Major defect at MOT (automatic fail) until the fault is repaired and the light stays off.

Before booking your test, check what usually fails on your car: see our MOT pass rates by make and model, built from 33.1 million DVSA tests.

Related guides

Car diagnostic test cost: compare the scopeUK booking marketplaces currently publish diagnostic averages of about £52–£65. Engine management light on: steady or flashing?A steady engine management light means the computer has stored a fault. Drive with caution and get the code read. A flashing light is different — stop when it is safe.
P0100Mass or Volume Air Flow Circuit P0101Mass or Volume Air Flow Circuit Range/Performance P0102Mass or Volume Air Flow Circuit Low Input P0103Mass or Volume Air Flow Circuit High Input P0104Mass or Volume Air Flow Circuit Intermittent P0105Manifold Absolute Pressure/Barometric Pressure Circuit P0106Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance P0107Manifold Absolute Pressure/Barometric Pressure Circuit Low Input

P0198 — quick answers

Is it safe to drive with P0198?

Do not drive until checked. We have no verified driving guidance for P0198. This page will not invent a milder drive class. Park the car and have the oil-temperature circuit checked before you use it again.

Will P0198 fail my MOT?

A lit engine management light is a Major defect at MOT (automatic fail) until the fault is repaired and the light stays off.

Fault-code identifiers are standard diagnostic facts. Their explanations and diagnostic guidance on this site are original editorial summaries, not reproduced SAE wording. MOT defect rules reflect the DVSA MOT inspection manual (2026). This page is general guidance for UK drivers, not a substitute for a professional diagnosis.