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DTC/P0354

P0354: Ignition Coil D Primary/Secondary Circuit Malfunction

Quick Answer
Moderata GravitàNon sicuro da guidareAccensione

P0354 means the ECU saw an electrical fault in the primary or secondary circuit driving ignition coil #4. Cylinder 4 isn't getting reliable spark, so expect a misfire and a flashing CEL under load.

Costo di riparazione stimatoDa €48 a €1450+, varia in base al veicolo

Scansiona la tua auto in circa 60 secondi: scopri se P0354 è davvero presente, quanto è urgente e quanto dovrebbe costare la riparazione.

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Cosa significa P0354?

P0354 means the ECU saw an electrical fault in the primary or secondary circuit driving ignition coil #4. Cylinder 4 isn't getting reliable spark, so expect a misfire and a flashing CEL under load.

P0354 è un codice diagnostico di guasto relativo a accensione, classificato con gravità moderate. Quando la centralina (ECU) del tuo veicolo rileva questa condizione, memorizza P0354 e accende la spia motore.

Quali sono i sintomi di P0354?

Se il tuo veicolo ha attivato P0354, potresti notare uno o più di questi sintomi:

  • Rough idle, worst when cold
  • Stumble or dead spot under acceleration
  • Flashing check engine light when the misfire is active
  • Raw fuel smell from the tailpipe
  • 10 to 20 percent drop in fuel economy
  • Loss of power above 3000 rpm
  • Occasional pop or backfire through the exhaust

Cosa causa P0354?

Ecco le cause più comuni di P0354:

altaFailed ignition coil on cylinder 4
altaWorn or fouled spark plug on cylinder 4
mediaDamaged coil connector or corroded pins
mediaBroken wire in the coil harness (power, ground, or trigger)
bassaOil in the spark plug well from a leaking valve cover gasket
bassaECU coil driver transistor failure

È sicuro guidare con P0354?

No, risolvi subito il problema. You can limp home, but unburned fuel dumps into the exhaust and cooks the catalytic converter. Fix within a day or two, not weeks.

Come si diagnostica P0354?

Segui questi passaggi per individuare la causa principale di P0354:

  1. Read all stored codes. Note any P030X misfire codes or other coil circuit codes for context.
  2. Swap coil #4 with coil #1 or #2, clear codes, and drive. If the fault follows the coil, replace it.
  3. Pull spark plug #4 and inspect gap, electrode wear, oil, fuel, or carbon fouling.
  4. Unplug the coil connector and check for bent pins, green corrosion, or oil contamination.
  5. Key on, engine off: confirm battery voltage on the coil power pin against a known good ground.
  6. Back-probe the ECU trigger wire while cranking and confirm a switching signal with a scope or noid/LED test light.
  7. Measure primary resistance (typically 0.4 to 2 ohms) and secondary (5k to 15k ohms) against factory spec.
  8. If coil, plug, connector, and wiring all pass, suspect the ECU driver circuit for cylinder 4.

Quanto costa riparare P0354?

I costi di riparazione di P0354 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 #4 €25–€120 €30–€90 €55–€210 Facile
Replace spark plug #4 (or full set) €8–€80 €40–€150 €48–€230 Facile
Repair coil harness connector or wiring €10–€40 €60–€180 €70–€220 Moderata
Valve cover gasket replacement (oil-fouled plug well) €30–€120 €120–€350 €150–€470 Moderata
ECU repair or replacement (rare) €400–€1200 €100–€250 €500–€1450 Professionale

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

P0354 su veicoli specifici

P0354 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

P0354 su Ford F-150

2004-2014

5.4L 3V Triton is notorious for coil-on-plug failure. Boots crack, moisture gets in, and the two-piece spark plugs (TSB 08-1-9) often snap off in the head during removal. Use Motorcraft coils and Champion/Motorcraft plugs with anti-seize.

Cosa causa P0354 su una Ford F-150?

Ford F-150Cracked coil boot arcing to the plug well
Ford F-150Two-piece spark plug breaking off in the head during removal
Ford F-150Water intrusion after washing the engine bay

Costo di riparazione di P0354 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 #4 €28–€132 €33–€99 €61–€231 Facile
Replace spark plug #4 (or full set) €9–€88 €44–€165 €53–€253 Facile
Repair coil harness connector or wiring €11–€44 €66–€198 €77–€242 Moderata
Valve cover gasket replacement (oil-fouled plug well) €33–€132 €132–€385 €165–€517 Moderata
ECU repair or replacement (rare) €440–€1320 €110–€275 €550–€1595 Professionale

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

Volkswagen

P0354 su VW Golf

2006-2016

1.4 TSI (CAVD/CTHD) and 2.0 TFSI (BPY, CCTA) went through several coil revisions. VW part 06H905115 has superseded through B, C, E, F, and later suffixes. Fit the latest revision as a set, not just cylinder 4.

Cosa causa P0354 su una VW Golf?

VW GolfEarly-revision 06H905115 coils failing around 80,000 km
VW GolfCarbon-loaded intake valves on FSI/TSI worsening the misfire
VW GolfWeak red locking clip on the coil connector letting it back out

Costo di riparazione di P0354 per VW Golf

Costi stimati per i proprietari di VW Golfadeguato al rialzo rispetto alla media a causa dei prezzi dei ricambi specifici Volkswagen

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Replace ignition coil #4 €29–€138 €35–€103 €63–€241 Facile
Replace spark plug #4 (or full set) €9–€92 €46–€173 €55–€265 Facile
Repair coil harness connector or wiring €12–€46 €69–€207 €81–€253 Moderata
Valve cover gasket replacement (oil-fouled plug well) €35–€138 €138–€402 €173–€541 Moderata
ECU repair or replacement (rare) €460–€1380 €115–€288 €575–€1667 Professionale

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

BMW

P0354 su BMW 3-Series

2007-2015

N54 (335i) and N55 (335i/435i) hammer coils when the plugs are past their 60,000 km interval. Stick with OEM Bosch or Delphi coils. On the N54, also rule out cracked charge pipes and injector index issues before condemning the coil.

Cosa causa P0354 su una BMW 3-Series?

BMW 3-SeriesOverdue plugs causing coil overheating and dielectric breakdown
BMW 3-SeriesCheap eBay coils failing within a few thousand km
BMW 3-SeriesCracked plastic charge pipe (N54) causing lean misfires misread as ignition

Costo di riparazione di P0354 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 #4 €31–€150 €38–€113 €69–€263 Facile
Replace spark plug #4 (or full set) €10–€100 €50–€188 €60–€288 Facile
Repair coil harness connector or wiring €13–€50 €75–€225 €88–€275 Moderata
Valve cover gasket replacement (oil-fouled plug well) €38–€150 €150–€438 €188–€588 Moderata
ECU repair or replacement (rare) €500–€1500 €125–€313 €625–€1813 Professionale

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

Toyota

P0354 su Toyota Camry

2002-2018

2AZ-FE and 2AR-FE rarely lose coils. When P0354 appears on a Camry it's usually plugs left past 160,000 km or oil in the plug tubes from a leaking valve cover gasket. Denso FK20HR11 iridium is the correct plug for most 2AR-FE builds.

Cosa causa P0354 su una Toyota Camry?

Toyota CamryOriginal spark plugs left past 160,000 km
Toyota CamryValve cover gasket leaking oil into the plug tubes
Toyota CamrySingle coil failure (uncommon, replace individually)

Costo di riparazione di P0354 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 #4 €21–€102 €26–€77 €47–€179 Facile
Replace spark plug #4 (or full set) €7–€68 €34–€128 €41–€196 Facile
Repair coil harness connector or wiring €9–€34 €51–€153 €60–€187 Moderata
Valve cover gasket replacement (oil-fouled plug well) €26–€102 €102–€298 €128–€400 Moderata
ECU repair or replacement (rare) €340–€1020 €85–€213 €425–€1233 Professionale

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

Honda

P0354 su Honda Civic

2006-2015

R18A1 (1.8L) and K24Z7 (Si 2.4L) rarely fail coils outright. Check the coil sub-harness where it runs along the valve cover, it chafes on the cover edge and cuts the trigger wire. Also inspect the plug tube seals in the valve cover gasket.

Cosa causa P0354 su una Honda Civic?

Honda CivicChafed trigger wire at the valve cover edge
Honda CivicOil in plug tubes from worn spark plug tube seals
Honda CivicNon-OEM coils with incorrect dwell characteristics

Costo di riparazione di P0354 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 #4 €23–€108 €27–€81 €50–€189 Facile
Replace spark plug #4 (or full set) €7–€72 €36–€135 €43–€207 Facile
Repair coil harness connector or wiring €9–€36 €54–€162 €63–€198 Moderata
Valve cover gasket replacement (oil-fouled plug well) €27–€108 €108–€315 €135–€423 Moderata
ECU repair or replacement (rare) €360–€1080 €90–€225 €450–€1305 Professionale

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

Questi codici compaiono spesso insieme a P0354 o indicano problemi correlati:

Domande frequenti su P0354

Which cylinder is coil D on P0354?

Coil D is cylinder 4 on virtually every application. On inline engines count from the front (timing) end. On V engines check the firing order and bank layout in the service data, since cylinder numbering isn't the same across manufacturers.

Can I just swap coils to test?

Yes, and it's the fastest test on the car. Move coil 4 to another cylinder, clear the code, and drive. If the code jumps to the new cylinder, the coil is bad. If P0354 stays, look at the plug, connector, or wiring.

Will P0354 damage my catalytic converter?

Yes if you keep driving on it. Raw fuel entering a hot cat overheats the substrate and melts it. A €60 coil now beats a €900 catalyst later, which is why the ECU flashes the CEL during an active misfire.

Why did P0354 come back after I replaced the coil?

Usually one of three things: the replacement coil is defective out of the box (common with cheap aftermarket), the spark plug is fouled or gapped wrong, or there's a broken wire or bad pin in the connector that's still cutting the trigger signal.

Can a bad fuel injector set P0354?

No. A dead injector on cylinder 4 typically sets P0204 or a cylinder-4 misfire (P0304). P0354 is strictly an ignition primary or secondary circuit electrical fault, not a combustion or fuel fault.

Leggi le nostre guide dettagliate

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Esegui la scansione della tua auto con Skanyx per diagnosticare P0354

La tua auto ha registrato P0354. 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 €48-€1450 così conosci la cifra prima che un'officina ti faccia un preventivo.

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