If you're working on a 2022+ Volkswagen Group vehicle with DQ381 (or DQ380/DQ500) Gen2 gearbox, you've likely run into the infamous BH1G0401 bootloader. This security lock has made mileage correction and tuning difficult for many tools.
The good news? Several solutions now exist. Here's a practical comparison of some tools that can handle the job: Autotuner, Flex, Yanhua ACDP, and OBDSTAR X300 Classic G3/DC706.
Tool Comparison
| Feature | Autotuner | Flex | Yanhua ACDP | OBDSTAR X300 G3 / DC706 |
| DQ38x Gen2 2022+ (401 Loader) Support | ✅ Yes (New AT Protocol) | ✅ Yes (v7.52.0.0+) | ✅ Yes (Module 45/Module 19/Module 25/Module 30) | ✅ Yes (Free Upgrade) |
| Method | Bench unlock, then OBD flash | Bench mode (read/write/maps/EEPROM) | Bench | Bench mode |
| Required Cable | Dedicated DQ38x bench cable or DSG bnech cables kit | Flex TCU OBD/Bench/Boot software package | Yanhua Module 45 license + ACDP hardware | TCM-005 cable (for DQ38x) |
| MCU | SH72549 | Not specified | Not specified | Not specified |
| Key Functions | OBD/Bench/Boot ECU & TCU tuning, Automatic checksum calculation, back to stock | Read/Write/Checksum Calculation Maps, Read/Write Internal EEPROM, Full Backup | Data reading and writing, Mileage correction | Data reading and writing, Mileage Calibration, IMMO data decryption |
Tool-by-Tool Breakdown
Best for: Professional tuners who want speed and a bench-to-OBD workflow.
Autotuner has released a new AT Protocol specifically for the 401 loader. The workflow is clever: unlock on the bench, then flash via OBD for subsequent operations.
Key specs:
- MCU: SH72549
- Bench read: 3min 30sec
- Bench write: 30sec
- OBD write: 1min 30sec
- Includes checksum correction, back-to-stock function (OBD only) and backup creation (Bench only)
This protocol requires one of those specific cables:
- Dedicated DQ38x bench cable
- DSG bench cables kit
Supported vehicles: Golf 8 R, Formentor, S3, and all 2.0 TSI/TDI models with the 401 bootloader.
Compatibility List
- Audi Models: A1 (2018) / A3 (2012 – 2019) / A4 (2008 – 2018) / A5 (2011 – 2016) / A6 (2011 – 2018) / Q2 (2016 – 2021) / Q3 (2011 – 2018) / Q5 (2012 – 2017) / S3 (2020) / SQ2 (2018) / TT (2018) / TT S (2018)
- Audi Engines: 2.0 TSI / 40 TFSI (2.0) / 2.0 TDI CR EU6 / 2.0 TFSI OPF / 40 TDI (2.0) / 40 TFSI (2.0) EU6d / 2.0 TSI EU6d / 45 TFSI (2.0) / 2.0 TSI R EU6d / 2.0 TFSI (S) EU6d / 45 TFSI (2.0) EU6d
- Cupra Models: Ateca (2019) / Formentor (2020) / Leon (2020)
Cupra Engines: 2.0 TSI EU6d / 2.0 TDI CR EU6 / 2.0 TSI VZ / 2.0 TSI
- Seat Models: Alhambra (2015) / Ateca (2016 – 2020) / Leon (2013 – 2020) / Tarraco (2019)
Seat Engines: 2.0 TDI CR EU6 / 2.0 TFSI OPF / 2.0 TDI CR EU6.2 / 2.0 TSI EU6d / 2.0 TSI FR
- Skoda Models: Karoq (2017 – 2022) / Kodiaq (2017 – 2023) / Octavia (2013 – 2020) / Superb (2015 – 2019) / Yeti (2008 – 2014)
Skoda Engines: 2.0 TDI CR EU6 / 2.0 TFSI OPF / 2.0 TDI CR EU6.2 / 2.0 TSI EU6d / 2.0 TSI / 2.0 TSI RS / 2.0 TSI EU6
- Volkswagen Models: Arteon (2017 – 2020) / Atlas (2018) / Caddy (2015 – 2021) / Coccinelle / Beetle (2011) / Golf (2012 – 2024) / Golf Sportvan (2014) / Jetta (2010 – 2018) / Lavida (2018) / Passat (2015 – 2023) / Passat CC (2013) / Polo (2021) / Scirocco (2014) / Sharan (2015) / T-Roc (2017) / Talagon (2021) / Taos (2020) / Tavendor (2022) / Tayron (2018) / Teramont (2018) / Tharu (2018) / Tiguan (2016 – 2021) / Touran (2016) / Viloran (2020)
Volkswagen Engines: 2.0 TDI CR EU6 / 2.0 TFSI OPF / 2.0 TDI CR EU6.2 / 2.0 TSI R / 2.0 TSI EU6 / 2.0 TSI EU6d / 2.0 TFSI EU6 / 2.0 TSI / 2.0 TFSI (ClubSport) / 2.0 TSI GTI / 2.0 TSI R 20 Years / 2.0 TSI (GLI) / 2.0 TSI EU6 (380) / 2.0 TSI 4 motion / 2.0 TSI R EU6d / 330 TSI
Best for: Tuners who need a single platform for multiple TCU types (DQ500 Gen2, ZF AL552).
Flex introduced support in version 7.52.0.0 (and later v6.35.0.0 according to earlier notes) for:
- VAG Bosch DQ500 Gen2 (2022+)
- VAG Bosch DQ38x Gen2 (2022+)
- VAG ZF AL552 Gen2 (2022+)
Capabilities (via Bench mode):
- Read/Write full TCU data
- Checksum calculation for maps
- Read/Write internal EEPROM
- Full backup creation
Supported vehicles include:
- Audi RS6 (C8) 4.0 V8
- Lamborghini Urus
- Porsche Cayenne (III)
- Cupra Formentor
- VW Golf VIII GTI
- Skoda Octavia IV
Flex requires a software package (FLS0.2M Master, FLS0.2S Slave, or FLS0.5M Full Master or FLS0.5S Full Slave) with TCU OBD/Bench/Boot capabilities.
3.Yanhua Mini ACDP
Best for: Shops focused on mileage correction, especially if you already own the ACDP platform.
What do you need?
- Mini ACDP1 with ACDP1 Module 45
- Mini ACDP2with ACDP2 Module 45
- If you have already purchased ACDP Module 19/ACDP2 Module 19, ACDP Module 25/ACDP2 Module 25or ACDP Module 30/ACDP2 Module 30, just need to purchase Module 45 license (A60B) to use the function directly.
Reference:
http://blog.eobdtool.co.uk/how-to-read-and-write-2022-vw-dq38x_gen2-data-by-yanhua-acdp2/
How to Correct Mileage on 2022+ VW DQ38x Gen2 by Yanhua ACDP2?
- OBDSTAR X300 Classic G3 / DC706
Best for: Repair shops that already own an OBDSTAR platform and want a budget-friendly mileage solution.
OBDSTAR released a free upgrade adding bench-mode support for:
- BOSCH DQ380/DQ381/DQ500 GEN2 → requires TCM-005 cable
- ZF AL552 GEN2 → requires TCM-024 cable
Supported bootloader: BH1G0401
Functions:
- Data read/write
- Mileage calibration
- IMMO data decryption (exclusive feature for Bosch units)
Compatible devices:
- OBDSTAR X300 Classic G3 Full Version
- OBDSTAR X300 Classic G3with ECU/TCU Cloning License
- OBDSTAR DC706 ECU Tool(Full Version)
Vehicle brands supported: VW, Audi, Skoda, Porsche, Bentley, Lamborghini
Note: You may need to purchase the mileage correction license separately depending on your device configuration.
Reference:
http://blog.eobdtool.co.uk/obdstar-g3-dc706-free-upgrade-dq38x-dq500-gen2-tcm-clone-bench-mode/
Final Recommendations
| Your Profile | Recommended Tool |
| Professional tuner (high volume) | Autotuner ECU Programmer or Flex ECU Chip Tuning Tool– both offer fast workflows, frequent updates, and full tuning capabilities beyond mileage |
| Repair shop doing occasional mileage corrections | OBDSTAR G3/DC706 ECU Tool – cost-effective if you already own the platform |
| Specialist in immobilizer/mileage work | Yanhua Mini ACDP with Module 45/30/25/19 – powerful and focused, but make sure you buy the right module |
| Need to also work on ZF AL552 | Flex or OBDSTAR (with TCM-024) – both support the ZF units |