P0065 fault code: Air Assisted Injector Control Range/Performance

P0065 means “Air Assisted Injector Control Range/Performance” — a fuel and air metering fault in the powertrain.

Can I DIY?

Professional-only boundary. Confirm the code only; air-assist hardware is not a driveway repair on this page.

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 P0065

Do not drive. On engines that blow extra air past an injector to help atomise fuel, the computer thinks that air-assist control is outside its expected range. Idle and cold-start mixture can drift even if the injector still clicks.

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

  • Air Assisted Injector Control Range/Performance: Registration number
  • Air Assisted Injector Control Range/Performance: Exact code P0065 and any companion codes
  • Air Assisted Injector Control Range/Performance: Whether the engine management light is steady or flashing
  • Air Assisted Injector Control Range/Performance: Whether the handbook or a technician has confirmed the engine uses air-assisted injectors
P00xxFuel and air metering
MOT fail riskif the warning light stays on

What does P0065 mean?

P0065 is a generic (SAE standard) powertrain code reported by your car’s engine control unit. It sits in the P00xx block, which covers fuel and air metering. The stored description is “Air Assisted Injector Control Range/Performance”. The code itself tells you which circuit or system tripped the fault — not always the exact part that failed.

Will P0065 fail an MOT?

If the engine management light is on, MOT treats it as a Major fail. Air-assisted injector performance is not a named MOT inspection heading of its own.

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.
P0001Fuel Volume Regulator Control Circuit/Open P0002Fuel Volume Regulator Control Circuit Range/Performance P0003Fuel Volume Regulator Control Circuit Low P0004Fuel Volume Regulator Control Circuit High P0005Fuel Shutoff Valve 'A' Control Circuit/Open P0006Fuel Shutoff Valve 'A' Control Circuit Low P0007Fuel Shutoff Valve 'A' Control Circuit High P0008Engine Position System Performance

P0065 — quick answers

Is it safe to drive with P0065?

Do not drive. P0065 has no verified driving guidance. Treat as do not drive until a workshop has confirmed whether air-assist is even fitted on your engine. Guessing at injector air pipes is not a driving plan.

Will P0065 fail my MOT?

If the engine management light is on, MOT treats it as a Major fail. Air-assisted injector performance is not a named MOT inspection heading of its own.

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.