Bank 1 sensor 1 heater circuit fault on Audi TFSI — connector heat damage common on longitudinal engines.
Audi P0030 — Bank 1 sensor 1 heater circuit fault on Audi TFSI — connector heat damage common on longitudinal engines. Typical UK independent garage cost: £100–£340.
What actually causes P0030 on a Audi
A4 B8 2.0 TFSI: the upstream sensor sits inches from the turbo and the four-pin connector melts on cars parked hot. Heater circuit opens intermittently first, then permanently. 3.0 TFSI S4: usually the sensor itself as it's a twin-flow design that stresses the heater element.
Audi engines that log P0030
- 2.0 TFSI EA888 (A4 B8, A5)
- 3.0 TFSI EA837 (S4, S5, Q5)
- 1.4 TFSI EA211 (A1, A3)
How we diagnose P0030 on a Audi
- VCDS full scan and readiness monitor status
- Heater resistance at sensor — 3–10Ω cold, open = sensor or connector
- Inspect connector housing for melt, replace pigtail with OEM repair harness (£45)
- Bosch OE sensor only, reset readiness monitors after fit
The common misdiagnosis to avoid
Coding out the fault with VCDS — it comes back at next MOT emissions check. Also, don't fit a NTK sensor on 3.0 TFSI; Audi ECM logs P0133 for slow response on non-Bosch parts.
Audi P0030 repair cost in the UK
Expect £100–£340 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
A4 B8 2.0 TFSI — the OEM pigtail repair harness from Audi is worth every penny. Pattern connectors melt again.
Codes usually seen alongside P0030 on Audi
- P0031
- P0133
- P0135
Symptoms drivers report with P0030
- Engine warning light comes on within 1–3 miles of a cold start every time
- MPG drops 3–6 in short-trip city driving (ECU can't close-loop until the sensor's warm)
- MOT emissions test failure on CO or HC when the tester samples cold
- Sooty smell from the exhaust on start-up, especially on frosty mornings
- No drivability issue — car pulls normally, no misfire, no limp
- Sometimes clears itself after a 30-minute motorway run then returns overnight
- Often paired with P0031 (heater low) or P0032 (heater high) — same sensor circuit
Repairs that clear P0030
- Replace O2 sensor
- Check fuse and wiring
For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0030 guide.