Volkswagen P0340

Camshaft position sensor on VAG — Hall sensor failure on 1.4/1.6 FSI and 2.0 TDI common rail.

Volkswagen P0340 — Camshaft position sensor on VAG — Hall sensor failure on 1.4/1.6 FSI and 2.0 TDI common rail. Typical UK independent garage cost: £65–£280.

What actually causes P0340 on a Volkswagen

VAG cam sensors (Hall-effect type) suffer heat-related failure around 80-120k. On 2.0 TDI CR engines the sensor is at the back of the head and is a fiddly job. Rough cold-start and long crank are typical accompanying symptoms.

Volkswagen engines that log P0340

• 1.4 TSI EA111/EA211
• 1.6 FSI BLF/BAG
• 2.0 TDI CR (CFFB/CBAB/CFGB)
• 1.9 TDI PD (BKC/BXE)

How we diagnose P0340 on a Volkswagen

1. Scan for P0341 alongside (correlation vs hard fault)
2. Inspect harness routing for chafe
3. Test sensor signal with oscilloscope or live data
4. Use OEM/VAG sensor — pattern parts have failed quickly in our bay

The common misdiagnosis to avoid

Don't replace the sensor without checking the harness — chafed wiring against the cam cover bolt is a known cause that returns within weeks.

Volkswagen P0340 repair cost in the UK

Expect £65–£280 including parts and labour at an independent garage. Main-dealer quotes on Volkswagen 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.

Bob's workshop tip

VAG 2.0 TDI CR — order the cam sensor on the same job as a fuel filter and you'll be in and out in 90 minutes.

Codes usually seen alongside P0340 on Volkswagen

• P0341
• P0016

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.

Reading P0340 on a Volkswagen properly

A generic reader will show P0340 and nothing else. What matters is the freeze-frame data stored with it — engine speed, load, coolant temperature and fuel trims at the moment the fault was logged — plus whether any other module on the Volkswagen has logged something at the same time. Codes rarely arrive alone, and the order they were stored in usually points at which one is the cause and which are the consequences.

Clearing P0340 without fixing it

Erasing the code resets the Volkswagen's readiness monitors as well as the light. The fault returns on the next drive cycle if the cause is still there, and in the meantime the incomplete monitors can stop the car passing an emissions check. After a genuine repair, the car is driven until the relevant monitor completes before it is handed back.

Bob's Mechanical Repairs is an independent garage in Birnam, Dunkeld, Perthshire, with 32 years of Bob's experience on the tools. If P0340 is showing on your Volkswagen, bring any scan results with you — we will read the live data ourselves, confirm which cause it actually is, and price the repair before any work starts.