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DTC/P0351

P0351: Ignition Coil A Primary/Secondary Circuit Malfunction

Quick Answer
Moderata GravitàNon sicuro da guidareAccensione

P0351 means the ECU saw an electrical fault in the primary or secondary circuit of ignition coil #1. Usually a failed coil, sometimes wiring, connector, or the ECU's ignition driver.

Costo di riparazione stimatoDa €55 a €1800+, varia in base al veicolo

Scansiona la tua auto in circa 60 secondi: scopri se P0351 è davvero presente, quanto è urgente e quanto dovrebbe costare la riparazione.

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Cosa significa P0351?

P0351 means the ECU saw an electrical fault in the primary or secondary circuit of ignition coil #1. Usually a failed coil, sometimes wiring, connector, or the ECU's ignition driver.

P0351 è un codice diagnostico di guasto relativo a accensione, classificato con gravità moderate. Quando la centralina (ECU) del tuo veicolo rileva questa condizione, memorizza P0351 e accende la spia motore.

Quali sono i sintomi di P0351?

Se il tuo veicolo ha attivato P0351, potresti notare uno o più di questi sintomi:

  • Rough idle with a clear cylinder 1 misfire you can feel through the steering wheel
  • Check engine light on, flashing when the misfire is active under load
  • Power loss and hesitation on acceleration, especially uphill
  • Fuel economy drop of roughly 10 to 20 percent
  • Raw fuel smell from the tailpipe after a few minutes of running
  • Longer cranking before the engine catches

Cosa causa P0351?

Ecco le cause più comuni di P0351:

altaFailed ignition coil #1 (internal winding open or shorted)
altaCorroded or oil-contaminated coil connector on cylinder 1
mediaCracked coil boot arcing to the head or plug well
mediaWorn spark plug with excessive gap overstressing the coil
bassaChafed or broken wire between ECU and coil primary
bassaFailed ECU ignition driver transistor for cylinder 1

È sicuro guidare con P0351?

No, risolvi subito il problema. You can limp home, but don't keep driving on it. A dead coil dumps raw fuel into the exhaust and cooks the catalytic converter fast. Replacement cats run €600 to €1500 on most cars.

Come si diagnostica P0351?

Segui questi passaggi per individuare la causa principale di P0351:

  1. Scan for all stored codes. A P0301 alongside P0351 confirms cylinder 1 is the misfiring cylinder, not just an electrical hiccup.
  2. Pull the coil #1 connector and inspect for green corrosion, bent pins, or oil from a leaking valve cover gasket.
  3. Swap coil #1 with coil #3 (or any other cylinder), clear codes, and drive. If P0353 now appears, the coil is dead. If P0351 stays, the fault is wiring or ECU side.
  4. Pull spark plug #1. Check for excessive gap, oil fouling, or a cracked insulator. Replace it regardless while you're in there.
  5. Measure coil primary resistance (typically 0.4 to 2 ohms) and secondary (5k to 15k ohms). Compare to your service manual spec, not a generic number.
  6. Key on, engine off: confirm 12V at the coil power pin. Then back-probe the trigger wire and check for a switching signal while cranking.
  7. Trace the trigger wire back toward the ECU looking for chafe points, especially where the harness crosses the valve cover or a metal bracket.
  8. If coil, plug, power, and trigger wire all pass, scope the ECU driver output. A flat line while cranking points to a failed driver inside the ECU.

Quanto costa riparare P0351?

I costi di riparazione di P0351 variano a seconda della causa principale e del tuo veicolo. Ecco le stime tipiche:

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Replace ignition coil #1 only €25–€120 €30–€90 €55–€210 Facile
Replace coil #1 plus spark plug on cylinder 1 €35–€150 €40–€110 €75–€260 Facile
Full coil set and spark plug set replacement €120–€500 €80–€250 €200–€750 Moderata
Repair coil connector pigtail or harness section €15–€80 €60–€200 €75–€280 Moderata
ECU repair or replacement (rare) €400–€1500 €100–€300 €500–€1800 Professionale

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

P0351 su veicoli specifici

P0351 si comporta in modo diverso a seconda del tuo veicolo. Seleziona la tua auto qui sotto per cause specifiche del modello, problemi noti e stime dei costi adeguate:

Ford

P0351 su Ford F-150

2004-2014

5.4L 3V Triton is notorious for cracked coil boots and COP arcing to the head. Ford TSB 08-7-6 covers coil boot updates. Motorcraft DG-521 outlasts most aftermarket units.

Cosa causa P0351 su una Ford F-150?

Ford F-150Cracked coil boot on 5.4L 3V arcing spark to the valve cover
Ford F-150Water intrusion into the coil connector from a blocked cowl drain

Costo di riparazione di P0351 per Ford F-150

Costi stimati per i proprietari di Ford F-150adeguato al rialzo rispetto alla media a causa dei prezzi dei ricambi specifici Ford

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Replace ignition coil #1 only €28–€132 €33–€99 €61–€231 Facile
Replace coil #1 plus spark plug on cylinder 1 €39–€165 €44–€121 €83–€286 Facile
Full coil set and spark plug set replacement €132–€550 €88–€275 €220–€825 Moderata
Repair coil connector pigtail or harness section €17–€88 €66–€220 €83–€308 Moderata
ECU repair or replacement (rare) €440–€1650 €110–€330 €550–€1980 Professionale

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

Volkswagen

P0351 su VW Golf

2006-2016

1.4 TSI EA111 and 2.0 TFSI EA113/EA888 share red-top coils (part 06E905115). VW revised to brown, then black top after mass failures. Replace as a set of four.

Cosa causa P0351 su una VW Golf?

VW GolfOriginal red-top coil (06E905115) failure, superseded by 06E905115F black-top
VW GolfCarbon buildup on intake valves on FSI/TSI worsening misfire and stressing the coil
BMW

P0351 su BMW 3-Series

2007-2015

N54 and N55 turbocharged sixes are hard on coils, average life 60,000 to 100,000 km. Use Bosch 0221504470 or Delphi OEM only. Replace NGK plugs (ILZKAR7B11) every second coil change.

Cosa causa P0351 su una BMW 3-Series?

BMW 3-SeriesOil in the spark plug tubes from a failed valve cover gasket (very common on N54/N55)
BMW 3-SeriesCheap aftermarket coils breaking down under boost pressure

Costo di riparazione di P0351 per BMW 3-Series

Costi stimati per i proprietari di BMW 3-Seriesadeguato al rialzo rispetto alla media a causa dei prezzi dei ricambi specifici BMW

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Replace ignition coil #1 only €33–€156 €39–€117 €72–€273 Facile
Replace coil #1 plus spark plug on cylinder 1 €46–€195 €52–€143 €98–€338 Facile
Full coil set and spark plug set replacement €156–€650 €104–€325 €260–€975 Moderata
Repair coil connector pigtail or harness section €20–€104 €78–€260 €98–€364 Moderata
ECU repair or replacement (rare) €520–€1950 €130–€390 €650–€2340 Professionale

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

Toyota

P0351 su Toyota Camry

2002-2011

2AZ-FE 2.4L coils (Denso 90919-02248) are among the most reliable in the industry, most failures happen after 200,000 km. Access is straight down through the valve cover, 10 minute job.

Cosa causa P0351 su una Toyota Camry?

Toyota CamryAge-related winding breakdown past 200,000 km on original Denso coils
Toyota CamryWorn iridium plugs (Denso SK16R11) at 160,000+ km pushing coil voltage demand too high

Costo di riparazione di P0351 per Toyota Camry

Costi stimati per i proprietari di Toyota Camryadeguato al ribasso rispetto alla media a causa dei prezzi dei ricambi specifici Toyota

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Replace ignition coil #1 only €23–€108 €27–€81 €50–€189 Facile
Replace coil #1 plus spark plug on cylinder 1 €32–€135 €36–€99 €68–€234 Facile
Full coil set and spark plug set replacement €108–€450 €72–€225 €180–€675 Moderata
Repair coil connector pigtail or harness section €14–€72 €54–€180 €68–€252 Moderata
ECU repair or replacement (rare) €360–€1350 €90–€270 €450–€1620 Professionale

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

Honda

P0351 su Honda Civic

2006-2015

R18A1 1.8L often throws P0351 from a corroded connector rather than a bad coil. Check the pigtail (Honda 30520-RNA-A01 connector) before ordering parts.

Cosa causa P0351 su una Honda Civic?

Honda CivicGreen corrosion on the coil connector terminals from moisture wicking down the harness
Honda CivicCracked coil housing from repeated removal during 160,000 km plug changes

Costo di riparazione di P0351 per Honda Civic

Costi stimati per i proprietari di Honda Civicadeguato al ribasso rispetto alla media a causa dei prezzi dei ricambi specifici Honda

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Replace ignition coil #1 only €21–€102 €26–€77 €47–€179 Facile
Replace coil #1 plus spark plug on cylinder 1 €30–€128 €34–€94 €64–€221 Facile
Full coil set and spark plug set replacement €102–€425 €68–€213 €170–€638 Moderata
Repair coil connector pigtail or harness section €13–€68 €51–€170 €64–€238 Moderata
ECU repair or replacement (rare) €340–€1275 €85–€255 €425–€1530 Professionale

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

Questi codici compaiono spesso insieme a P0351 o indicano problemi correlati:

Domande frequenti su P0351

Can I just swap coil 1 with coil 2 to test it?

Yes, that's the fastest way. Move coil 1 to another cylinder, clear the code, and drive. If P0352, P0353, or P0354 pops up, the coil is bad. If P0351 comes right back, look at the connector, wiring, or ECU driver.

Will P0351 wreck my catalytic converter?

Yes if you keep driving on it. Unburned fuel from the dead cylinder ignites in the cat and melts the substrate. A drive home is fine, a week of commuting on a flashing CEL usually isn't.

How long does it take to swap an ignition coil?

On most 4-cylinder coil-on-plug engines, 10 to 20 minutes. Two bolts and a connector. V6 or V8 engines with coils buried under an intake plenum (BMW N63, Audi 4.2 FSI) can take 1 to 3 hours.

My new coil failed within a month. Why?

Almost always one of three things: a worn spark plug you didn't replace, oil in the plug well from a leaking valve cover gasket shorting the boot, or a cheap aftermarket coil. Fix the root cause, use OEM (Bosch, Denso, Delphi, NGK), and it'll last.

Should I replace all the coils at once?

Not required, but if the car has 150,000+ km on original coils and one just died, the rest are close behind. On engines where labor is significant (BMW N54, VW/Audi TSI), replacing the set once is cheaper than four separate visits.

Leggi le nostre guide dettagliate

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Esegui la scansione della tua auto con Skanyx per diagnosticare P0351

La tua auto ha registrato P0351. Skanyx lo legge con qualsiasi adattatore OBD2 Bluetooth standard, ti dice se puoi continuare a guidare in sicurezza e mostra la fascia di riparazione di €55-€1800 così conosci la cifra prima che un'officina ti faccia un preventivo.

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