P0070 fault code: Ambient Air Temperature Sensor Circuit

P0070 means “Ambient Air Temperature Sensor Circuit” — a fuel and air metering fault in the powertrain.

Can I DIY?

Professional-only boundary. You may note the outside-temp display; replacing bumper sensors is garage work here.

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 P0070

Do not drive. The outside-air temperature sensor is not sending a usable circuit signal. Climate control and some cold-start or glow strategies that read ambient temperature can then use a substitute value.

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

  • Ambient Air Temperature Sensor Circuit: Registration number
  • Ambient Air Temperature Sensor Circuit: Exact code P0070 and any companion codes
  • Ambient Air Temperature Sensor Circuit: Whether the engine management light is steady or flashing
  • Ambient Air Temperature Sensor Circuit: What outside temperature the climate display showed, if anything
P00xxFuel and air metering
MOT fail riskif the warning light stays on

What does P0070 mean?

P0070 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 “Ambient Air Temperature Sensor Circuit”. The code itself tells you which circuit or system tripped the fault — not always the exact part that failed.

Will P0070 fail an MOT?

A lit engine management light is a Major MOT defect. Ambient-air temperature itself is not a MOT named inspection item.

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

P0070 — quick answers

Is it safe to drive with P0070?

Do not drive. P0070 has no verified driving guidance. Driveability is therefore not graded — treat as do not drive until checked rather than assuming an ambient sensor is harmless.

Will P0070 fail my MOT?

A lit engine management light is a Major MOT defect. Ambient-air temperature itself is not a MOT named inspection item.

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.