Turbo overboost on Audi — 2.0 TFSI EA113/EA888 wastegate actuator and 3.0 TFSI supercharger bypass.
Audi P0234 — Turbo overboost on Audi — 2.0 TFSI EA113/EA888 wastegate actuator and 3.0 TFSI supercharger bypass. Typical UK independent garage cost: £140–£850.
What actually causes P0234 on a Audi
Audi P0234 on EA113 is normally the N75 boost-control solenoid or a stuck wastegate. Stage-1+ remaps that exceed the wastegate's authority log P0234 routinely — check for tuning before parts.
Audi engines that log P0234
- 2.0 TFSI EA113 (A4/A6)
- 2.0 TFSI EA888 (A4/A5/Q5)
- 3.0 TFSI supercharged
How we diagnose P0234 on a Audi
- Check for ECU tuning
- N75 solenoid test
- Wastegate actuator manual sweep
- Smoke-test charge air for leaks
The common misdiagnosis to avoid
Mapped EA113s often log P0234 because the wastegate can't bleed enough boost — the map is the cause, not the turbo.
Audi P0234 repair cost in the UK
Expect £140–£850 including parts and labour at an independent garage. Main-dealer quotes on Audi 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
EA113 P0234 + Stage-1 map = customer-conversation job. Refer to tuner for remap revision.
Codes usually seen alongside P0234 on Audi
- P0299
- P2563
Symptoms drivers report with P0234
- The car goes into 'limp mode' (no power) specifically when accelerating hard up a hill in 4th or 5th gear.
- Engine picks up speed, then suddenly 'cuts out' or jerks, requiring you to turn the ignition off and back on to reset.
- A loud whistling or 'siren' noise under load that stops abruptly when the ECU cuts boost.
- The 'Service Engine Soon' or glow plug light flashing when you're trying to join a dual carriageway.
- The car feels unusually fast for a few seconds before the dash lights up and it loses all power.
Repairs that clear P0234
- Clean / replace VGT actuator
- Replace wastegate actuator
- Replace boost sensor
- Replace boost solenoid
- Inspect and replace boost vacuum pipework
For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0234 guide.