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DTC/P0354·BMW

P0354 on BMW: Causes, Symptoms and Fix Cost

Quick Answer
Moderate SeverityNot safe to driveBMW

P0354 on a BMW 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.

Typical repair cost, all makes€48 - €1450

Connect any standard Bluetooth OBD2 adapter to your BMW and Skanyx tells you what P0354 means on that engine, whether it is safe to keep driving, and what the fix should cost. Free on iPhone and Android.

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What does P0354 mean on a BMW?

The Quick Answer above is the generic definition. What follows is the model-specific detail for the BMW models that log P0354.

BMW 3-Series

2007-2015

N54 (335i) and N55 (335i/435i) are hard on coils when the plugs are past their service interval. Fit coils that match the original specification. On the N54, also rule out cracked charge pipes and injector index issues before condemning the coil.

What causes P0354 on a BMW?

Beyond the generic causes listed on the main P0354 page, these are the patterns noted for BMW models:

BMW 3-SeriesOverdue plugs causing coil overheating and dielectric breakdown
BMW 3-SeriesReplacement coil faulty from new, so recheck after any recent coil change
BMW 3-SeriesCracked plastic charge pipe (N54) causing lean misfires misread as ignition

How to diagnose P0354 on a BMW with OBD2

Follow these steps to pinpoint the root cause of 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.

How much does P0354 cost to fix on a BMW? (EUR)

Estimated repair costs for P0354 in EUR, compiled across makes. Expect BMW parts and labour towards the upper end of each range.

Repair Parts Cost Labor Cost Total Estimate DIY Difficulty
Replace ignition coil #4 €25–€120 €30–€90 €55–€210 Easy
Replace spark plug #4 (or full set) €8–€80 €40–€150 €48–€230 Easy
Repair coil harness connector or wiring €10–€40 €60–€180 €70–€220 Moderate
Valve cover gasket replacement (oil-fouled plug well) €30–€120 €120–€350 €150–€470 Moderate
ECU repair or replacement (rare) €400–€1200 €100–€250 €500–€1450 Professional

Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.

These codes are often seen alongside P0354 or point to related issues, on any make:

P0351BMWP0352P0353BMWP0355BMWP0304P0300BMW

Looking for the full P0354 reference (all makes, full diagnosis flow, complete repair cost matrix)?

See the main P0354 guide
Skanyx · BMW

Diagnose P0354 on your BMW

Your car logged P0354. Skanyx reads it on any standard Bluetooth OBD2 adapter, tells you whether it is safe to keep driving, and shows the €48-€1450 repair range so you know the number before a shop quotes you. Free on iPhone and Android, and you do not need to be a mechanic to read it.

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