Skip to the content
TunerSuite Your own ECU file portal, from £699 File service · upload 24/7 WhatsApp Client portal
Cart Try the demo
  1. Home
  2. Tuning files
  3. Stage3

Stage 3

Stage 3 · Diesel · 2.0 TDI Ultra (150) 150hp

Audi A6 1.8 T Stage 3 file Bosch HW 0261204256 · 4B0907557A · SW 357473

Audi A6 1.8 T 110.3 kW (150 HP) Stage 3

2004, 110.3 kW (150 hp)

150 → 225 HP +75 HP +171 Nm 50% more power

Calibrated ECU file for 0261204256 (SW 357473). Checksum-corrected, ready to flash. Delivered instantly via secure download after payment.

Performance projection

Matched engine: 2.0 TDI Ultra (150) 150hp, CSUD, 2.0L, Diesel. Engine #10723 in our gains database.

060120180240 10002000300040005000 225 HP +75 481 Nm +171 HP Nm RPM 0120240360480
Stock · Stage 3 · HP (left) · Nm (right) · Curve shape typical for this ECU family
Power
225 HP+75 HP from 150
Torque
481 Nm+171 Nm from 310
Fuel economy
−8 %−12% full load

Real data from Gains API. Dyno curve = typical ECU-family projection. Final gains depend on fuel, altitude, wear.

How it works

  1. Read your ECU

    With KESS, KTAG, AutoTuner or Flex. Keep the read: it is your way back.

  2. Match the numbers

    Your read must show hardware 0261204256 and software 357473.

  3. Pay and download

    Card, Apple Pay or Google Pay. The file is in your account straight away.

  4. Write it and drive

    Write it back the way you read it. Not right for your car? We correct it free.

What the car needs

Required modifications: Stage 3, Diesel.

Hardware

  • Hybrid or larger turbocharger
  • Upgraded injectors (matched flow rate)
  • Front-mount intercooler upgrade
  • Sport / decat downpipe + free-flow exhaust
  • High-flow air intake
  • Uprated clutch (manual gearbox)

Software / calibration

  • Custom map dialled to the installed turbo, injector and intercooler spec
  • Boost, fuelling, ignition / injection timing rebuilt around the new hardware
  • All safety limits (knock, EGT, lambda, rail) re-tuned to match
  • Drivability and torque-by-gear shaped to match the hardware

Stage 3 is hardware-matched. Send your turbo / injector / intercooler / clutch spec at checkout so the file is calibrated to YOUR build: typical projection above is a guide, final dyno depends on installed hardware.

Vehicle & ECU specifications

Exact vehicle, engine and ECU identifiers this calibration file is written for. Cross-check against your ECU before flashing.

Vehicle make Audi
Vehicle model A6
Model year 2004
Displacement 1.8 L
Factory power 110.3 kW (150 HP)
ECU manufacturer Bosch
ECU ID 4B0907557A
ECU hardware 0261204256
ECU software 357473
Calibration stage Stage 3
OEM engine code CSUD
File format BIN / ORI
Checksum Pre-corrected (ready to flash)
Delivery Instant download after payment

Engine performance matrix

Power, torque and fuel-economy figures for every tuning stage on this engine, sourced from the tuning-database Gains API. Values are healthy-engine crank numbers; real on-road gains vary with fuel, altitude and mechanical condition.

Engine2.0 TDI Ultra (150) 150hp CodeCSUD Displacement2.0L FuelDiesel Engine ID#10723
Stage Power Torque Δ HP Δ Nm
Original / Factory 150 HP 310 Nm — —
Stage 1 190 HP 390 Nm +40 (26.7%) +80
Stage 2 213 HP 456 Nm +63 (42%) +146
Stage 3 225 HP 481 Nm +75 (50%) +171
Stage 4 270 HP 574 Nm +120 (80%) +264
Fuel economy gain (vs. factory map, same driving profile): combined cycle −8% , full-load cruise −12%. Diesel calibrations typically net bigger combined-cycle savings thanks to shorter duty-cycle on low-load driving.

About this calibration file

The Stage 3 calibration for the 2004 Audi A6 1.8L targets a hardware-upgraded setup — hybrid or larger turbocharger, upgraded injectors, high-flow fuelling and in most cases a full exhaust. Maps are redrawn for the new airflow envelope with re-scaled MAF/MAP, torque limiters, smoke limiters and boost PID re-tuned.

This file matches a Bosch ECU with hardware number 0261204256 and software version 357473. Verify both identifiers in your flashing tool before writing — an ID mismatch is the most common cause of a bricked ECU. If you are unsure, upload a read of your original file via the file-request wizard and our engineers will confirm compatibility before you flash.

Projected output on a healthy, stock-hardware example of this engine: 225 HP and 481 Nm at the crank — a gain of +75 HP (50%) and +171 Nm over the factory 150 HP / 310 Nm baseline. These numbers are sourced from our Vehicle Performance Database, which aggregates dyno results across this engine family. Real-world gains depend on fuel grade, ambient temperature, mechanical condition and intake/exhaust state.

The file is delivered as a ready-to-flash BIN (and ORI backup where applicable) compatible with all major tools — KESS V2/V3, KTAG, AutoTuner, CMDFlash, Dimsport New Genius, MPPS, Flex, BFlash, PCMFlash, MMFlash — via OBD, bench or boot-mode as supported by your ECU family. Checksums are pre-computed and verified; no additional checksum tool is required. All files include a free revision if post-flash logs reveal a fuelling, boost or EGT issue.

Frequently asked questions

The file is written for the exact ECU hardware 0261204256 (Bosch) listed in the specifications. Read your ECU with any supported tool (KESS, KTAG, AutoTuner, CMD, etc.) and compare the hardware + software numbers against the ones on this page. If they match exactly, the file is a direct fit. If you're not 100% sure, upload your original read via the file-request wizard and our engineers will confirm within minutes — no cost, no obligation.

This stage targets a built setup — hybrid/larger turbo, upgraded injectors, high-flow fuelling, and in some cases upgraded transmission/clutch. Running the file on stock hardware is not supported and can cause detonation, EGT spikes or overboost fuel cuts.

Re-flashing the ECU leaves a flag that a franchised Audi dealer can detect with their diagnostic tool. Most markets treat this as a basis to deny powertrain warranty claims that the modification could have caused. Emissions-sensitive components (DPF, EGR, SCR) remain fully functional with this calibration — we do not remove, disable or alter any emissions hardware.

The power and torque numbers on this page are healthy-engine crank figures. On a well-maintained 2004 Audi A6 running a known-good fuel brand, you should see a clearly perceptible increase in mid-range pull — typically from 1,800 to 4,000 rpm on diesel, 2,500 to 6,000 rpm on petrol — along with a shorter 80-to-120 km/h in-gear time. Thermal performance and fuel consumption depend on how you drive post-tune.

Instant. As soon as the payment clears, the file appears under Downloads in your account and the link is emailed to you. It does not expire: sign in and download it again whenever you need it.

Pre-corrected. Every tuning file we sell is processed through CHKSuite (our in-house checksum engine) before it reaches your download link. You can flash it directly with KESS, KTAG, AutoTuner, CMD, Dimsport or any other supported tool — no extra checksum step required. A zero-CRC write to a modern Bosch/Siemens/Delphi ECU bricks the unit, so this is non-negotiable.

Contact us on WhatsApp or through the dashboard support thread. Free revisions are included for the same stage on the same ECU — send us a live log (via VCDS, INPA, EcuConnect, OBDeleven or similar) and we'll adjust timing, boost, rail pressure or smoke limits and re-issue the file. A failed flash itself (write aborted, bricked ECU) is recoverable with our Original file and a bench tool.

Product details

This product contains a calibrated Stage3 tuning file for Audi A6 1.8 T 2004 110.3KW with Bosch 0261204256 and software ID 4B0907557A (Bosch software number 357473 ( 1037357473 )). The base stock vehicle for this calibration has a factory output of around 110.3 kW (~150 HP). This high-stage file targets heavily modified setups (bigger turbo, injectors etc.) and should be used by experienced tuners only.

All ECU tuning files from TUNING-DATABASE are prepared for professional use. They are useful whenever you search by ECU ID, hardware or software number such as 0261204256, 4B0907557A, 357473 (1037 + SW code). Use this file for diagnostics, cloning, recovery or as a base for custom remapping.

SHA-256 fingerprint4ABA923C 8ED136BF 56E3C0D5 C06F7C14 5F765D65 A31021C1 616D3315 C203859D