P0351 fault code: Ignition Coil 'A' Primary/Secondary Circuit

Last updated · OBDCode UK editorial

P0351 means “Ignition Coil 'A' Primary/Secondary Circuit” — an ignition system and misfire fault in the powertrain. Do not drive. The engine computer reports a fault on ignition coil A's primary or secondary circuit, so that coil may not be firing. This page has no verified drive rating — do not drive until a garage checks it.

Can I DIY?

Caution — conditions apply. A related check or task may allow limited DIY with the stated tools and site conditions — only after you read the safety warnings on this page. We still do not publish full strip-down fitting steps here.

Caution — conditions applyDIY boundary
ToolsBasic tools only — for example a household socket set, tyre gauge, or a consumer OBD reader.

Some checks may be possible for a careful DIY driver with the right tools and a safe place to work. Stop if anything feels beyond your skill or kit.

12V electrical safety

On a 12V battery: disconnect negative first, reconnect negative last. Prevent sparks and short circuits. Stop if the battery is damaged or sits near orange high-voltage cables.

P03xxIgnition system and misfire
MOT fail riskif the warning light stays on

What does P0351 mean?

P0351 is a generic (SAE standard) powertrain code reported by your car’s engine control unit. It sits in the P03xx block, which covers ignition system and misfire. The stored description is “Ignition Coil 'A' Primary/Secondary Circuit”. The code itself tells you which circuit or system tripped the fault — not always the exact part that failed.

Will P0351 fail an MOT?

An illuminated engine management light is a Major defect at MOT 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.

What the MOT data says

No MOT certificate item corresponds to this code; MOT outcome data cannot be shown.

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. Flashing engine management light and juddering: stop and recoverNo — do not continue the journey. A flashing engine management light with the car juddering is a stop-driving situation: ease off only enough to reach the nearest place of relat…
P0300Random/Multiple Cylinder Misfire Detected P0301Cylinder 1 Misfire Detected P0302Cylinder 2 Misfire Detected P0303Cylinder 3 Misfire Detected P0304Cylinder 4 Misfire Detected P0305Cylinder 5 Misfire Detected P0306Cylinder 6 Misfire Detected P0307Cylinder 7 Misfire Detected

P0351 — quick answers

Is it safe to drive with P0351?

Do not drive. Driveability guidance is not available for this code — treat as do not drive until checked.

Can I fix P0351 myself?

Caution — conditions apply. A related check or task may allow limited DIY with the stated tools and site conditions — only after you read the safety warnings on this page. We still do not publish full strip-down fitting steps here. Basic tools only — for example a household socket set, tyre gauge, or a consumer OBD reader.

Will P0351 fail my MOT?

An illuminated engine management light is a Major defect at MOT 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.