Coil 4 fault.
P0354 — also written PO354, P 0354, 0354 — is the OBD-II code for ignition coil 'd' circuit. Same code, same fix: this page covers every spelling of it.
This code means your engine's brain has lost touch with the coil on cylinder number 4. It's a classic failure on high-mileage Vauxhalls and Fords where the coil pack breaks down under heat.
P0354 is a ignition fault code, typically costing £50–£350 to put right in a UK garage.
What P0354 actually feels like to drive
- The car feels like it's 'kangarooing' when you try to overtake on the A9.
- A heavy, rhythmic vibration through the steering wheel when idling at traffic lights.
- The engine sounds like a tractor and has lost all its 'get up and go'.
- Flashing Engine Management Light (EML) which usually means you're melting your catalytic converter.
- A strong smell of unburnt petrol coming from the exhaust pipe.
- The car struggles to pull away from junctions without stalling or 'chugging'.
What causes P0354?
- Coil failure
UK vehicles that throw P0354 most often
- Ford Focus 1.6 Ti-VCT (2008-2015)
- Vauxhall Astra J 1.4 Turbo (A14NET engine)
- Vauxhall Corsa D 1.2/1.4 (Z12XEP/Z14XEP)
- Volkswagen Golf Mk6 1.4 TSI (CAXA engine)
- Honda Civic 1.8 i-VTEC (R18A2) 2006-2011
- BMW 3 Series E90 (N43/N53 engines) 2007-2012
How P0354 is fixed
- Coil replacement
The P0354 misdiagnosis that wastes money
I see it every week: a customer arrives with a boot full of 'cheap and cheerful' spark plugs they’ve already swapped, thinking they’ve saved a fortune. When that doesn't work, they usually buy a single unbranded coil off eBay. The real kicker with the P0354 is often the wiring harness rubbing against the lift eye or the airbox bracket, especially on the Ford Duratec engines. You can swap coils until you're blue in the face, but if that signal wire is chafed through to the copper, you’re just chasing ghosts. Spend ten minutes with a multimeter before opening the parts catalogue.
What a UK garage should charge for P0354
For a decent Bosch or Delphi coil, you're looking at £45 to £90 for the part itself. Labour in a local independent like mine will run you about £50 to £70 for a diagnostic plug-in and the swap. Total bill? Usually between £110 and £160. If you go to a main dealer, expect to be quoted north of £300 once they've added their 'premium' diagnostic fee and 100% markup on the OEM part. If it turns out to be a melted ECU driver—heaven forbid—you're looking at a £500+ repair journey.
P0354 repair cost in the UK
Most P0354 repairs land between £50–£350 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Bob's tip on P0354
If you're taking it to a garage, ask them to 'loom test' the trigger wire for cylinder 4 specifically. A lot of lads will just swap the coil and send you on your way, only for the light to pop back on two days later because of a dodgy connector pin. Also, if your car has covered over 80k miles, don't just replace one coil. If coil D (number 4) has given up the ghost, its three brothers usually aren't far behind. Asking for a 'set of four' often works out cheaper on the labour than coming back three separate times when the others fail. Insist on Bosch, Delphi, or NGK—avoid the white-box specials if you want it to pass the next MOT emissions test.
Can you drive with P0354?
Drive gently.
Urgency: high.