P0063 fault code: HO2S Heater Control Circuit Low

Can I drive with P0063? — Do not drive

We have no verified driving guidance for P0063 — treat as do not drive until a garage has read the heater circuit. A cold oxygen sensor is an emissions issue, not a licence to keep using the car with the lamp on.

P0063 means “HO2S Heater Control Circuit Low” — a fuel and air metering fault in the powertrain.

Can I DIY?

Professional-only boundary. Scan and note the code only; heater-circuit repair 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 P0063

Do not drive. A heated oxygen-sensor heater is drawing too little current or sitting at too low a voltage, so that sensor can stay cold and mixture control stays crude until it warms by exhaust heat alone.

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

HO2S Heater Control Circuit Low: Registration number
HO2S Heater Control Circuit Low: Exact code P0063 and any companion codes
HO2S Heater Control Circuit Low: Whether the engine management light is steady or flashing
HO2S Heater Control Circuit Low: Which oxygen-sensor bank or sensor number the scanner showed, if any

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Fault code: P0063 — HO2S Heater Control Circuit Low.
Can I drive: Do not drive. We have no verified driving guidance for P0063 — treat as do not drive until a garage has read the heater circuit. A cold oxygen sensor is an emissions issue, not a licence to keep using the car with the lamp on.
Question: What does this code mean for a UK car, is it safe to drive, what are the most likely causes, and what should I ask a garage to check before replacing parts?

For your garage

REPAIR BRIEF — prepared by the owner with obdcode.co.uk
Fault code: P0063 — HO2S Heater Control Circuit Low.
Drive guidance from obdcode.co.uk: Do not drive. We have no verified driving guidance for P0063 — treat as do not drive until a garage has read the heater circuit. A cold oxygen sensor is an emissions issue, not a licence to keep using the car with the lamp on.
Owner’s request: please diagnose before replacing parts, itemise diagnosis time separately, and quote before any work beyond diagnosis.

P00xxFuel and air metering

MOT fail riskif the warning light stays on

What does P0063 mean?

P0063 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 “HO2S Heater Control Circuit Low”. The code itself tells you which circuit or system tripped the fault — not always the exact part that failed.

Will P0063 fail an MOT?

An illuminated engine management light is a Major MOT defect until it stays off. P0063 itself is a heater-circuit emissions monitor, not a separate MOT named 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.

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

P0063 — quick answers

Is it safe to drive with P0063?

Do not drive. We have no verified driving guidance for P0063 — treat as do not drive until a garage has read the heater circuit. A cold oxygen sensor is an emissions issue, not a licence to keep using the car with the lamp on.

Will P0063 fail my MOT?