P0354 on Toyota: Causes, Symptoms and Fix Cost
Quick Answer
Not safe to drive
P0354 on a Toyota 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.
- Severity
- Moderate · Ignition
- Typical repair cost, all makes
- €48-€1450
Connect a standard OBD2 adapter (Bluetooth LE on iPhone) to your Toyota 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.
Get Skanyx freeWhat does P0354 mean on a Toyota?
The Quick Answer above is the generic definition. What follows is the model-specific detail for the Toyota models that log P0354.
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.
What causes P0354 on a Toyota?
Beyond the generic causes listed on the main P0354 page, these are the patterns noted for Toyota models:
Original spark plugs left past 160,000 km
: Toyota Camry
Valve cover gasket leaking oil into the plug tubes
: Toyota Camry
Single coil failure (uncommon, replace individually)
: Toyota Camry
How to diagnose P0354 on a Toyota with OBD2
- Read all stored codes. Note any P030X misfire codes or other coil circuit codes for context.
- Swap coil #4 with coil #1 or #2, clear codes, and drive. If the fault follows the coil, replace it.
- Pull spark plug #4 and inspect gap, electrode wear, oil, fuel, or carbon fouling.
- Unplug the coil connector and check for bent pins, green corrosion, or oil contamination.
- Key on, engine off: confirm battery voltage on the coil power pin against a known good ground.
- Back-probe the ECU trigger wire while cranking and confirm a switching signal with a scope or noid/LED test light.
- Measure primary resistance (typically 0.4 to 2 ohms) and secondary (5k to 15k ohms) against factory spec.
- 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 Toyota? (EUR)
Estimated repair costs for P0354 in EUR, compiled across makes. Toyota parts and labour usually land towards the lower 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 October 2026. Costs vary by region, vehicle, and shop.
Codes related to P0354
These codes are often seen alongside P0354 or point to related issues, on any make:
Looking for the full P0354 reference (all makes, full diagnosis flow, complete repair cost matrix)? See the main P0354 guide