Camshaft position sensor circuit on Ford — failing CMP sensor on 1.6/2.0 TDCi and 1.0 EcoBoost wet-belt debris damaging the reluctor.
Ford P0340 — Camshaft position sensor circuit on Ford — failing CMP sensor on 1.6/2.0 TDCi and 1.0 EcoBoost wet-belt debris damaging the reluctor. Typical UK independent garage cost: £60–£2200.
What actually causes P0340 on a Ford
On the 1.0 EcoBoost, P0340 alongside any rough running is often early wet-belt failure — debris damaging the cam reluctor pattern. On 1.6 TDCi it's normally just a £40 sensor degrading with heat. Always check service history for the cambelt-in-oil change interval before condemning components.
Ford engines that log P0340
- 1.6 TDCi DV6 (Focus/C-Max/Fiesta)
- 2.0 TDCi (Mondeo/S-Max)
- 1.0 EcoBoost (Fiesta/Focus)
- 1.5/1.6 EcoBoost
How we diagnose P0340 on a Ford
- Read live cam vs crank signal correlation
- Inspect oil for belt debris (sump magnet / oil filter cut-open)
- Test CMP sensor resistance / signal at the ECU pin
- Confirm cambelt service interval against Ford's revised wet-belt schedule
The common misdiagnosis to avoid
P0340 on a high-mileage EcoBoost without a belt service is never just the sensor — replace the sensor and you'll be back in 3 weeks with timing failure.
Ford P0340 repair cost in the UK
Expect £60–£2200 including parts and labour at an independent garage. Main-dealer quotes on Ford are usually higher for the same job, and the spread exists because the cheap cause and the expensive cause throw the same code — pay for the diagnosis before you pay for parts.
Service campaign / TSB note
Ford revised 1.0 EcoBoost wet-belt interval down to 100k/10yr (originally lifetime).
Bob's workshop tip
EcoBoost P0340 + black sludge in oil filler = wet-belt job, not a sensor. Quote correctly first time.
Codes usually seen alongside P0340 on Ford
- P0341
- P0016
- P0017
Symptoms drivers report with P0340
- The car cranks for ages before finally firing up (limp mode start).
- Engine suddenly cuts out while waiting at a roundabout or junction.
- A noticeable lack of 'grunt' or pick-up, feeling like the turbo isn't boosting.
- The rev counter bounces erratically or drops to zero while driving.
- The car smells of unburnt petrol because the ECU is guessing the fuel timing.
Repairs that clear P0340
- Replace cam sensor (cheap, common fix)
- Repair wiring loom or connector
- On chain-driven engines, check chain wear before condemning sensor
For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0340 guide.