VW Audi Group SFD Diagnostic Firewall

September 15th 2026 - VCDS SFD access available on HEX-V2 and HEX-NET

Ross-Tech have released SFD unlocking access to all owners of (genuine) HEX-V2 & HEX-NET interfaces. See below for details.

VAG SFD?

Some 2020 model year and newer VW Audi Group (VAG) vehicles, are fitted with the "SFD" system.
SFD stands for 'Schutz der FahrzeugDiagnose', which directly translates to Vehicle Diagnostic Protection - essentially it's a diagnostic firewall.
SFD is fitted in the name of security and intercepts diagnostic requests and responses between the tool and the vehicle, and can block some diagnostic commands - particularly coding or adaptation commands which could make a change to the vehicle.

In order for these more advanced diagnostic requests to be allowed through, the control module you are connecting to will generate a 'challenge' token (an alphanumeric code which is unique to that diagnostic session). VAG's servers can use this to generate a 'release' token which, when presented back to the car, will unlock full access to that module for a set time period (typically 90 minutes).

VCDS (with a HEX-V2 or HEX-NET interface) now supports SFD unlocking. There are a few hoops to jump through though, largely to satisfy Volkswagen in Germany.

How do I sign up?

Ross-Tech have documented the full process with written instructions available here, and they also have a video version:

What will I need?

To access the SFD service you will need:

A genuine Ross-Tech HEX-V2 or HEX-NET VCDS interface, registered in your name.
To meet VW's strict data validation requirements, the interface MUST be registered to a single 'natural person', not a company or other entity.
If your interface is currently registered to your company, you will need to submit a registration change. (If the interface is company-owned though, Ross-Tech recommend using the company postal address on the registration, as this makes transfer of ownership more straightforward, should the nominated user leave the company).
The latest version of VCDS.
SFD in VCDS requires the latest available VCDS software version (available here), and the latest interface firmware to be installed.
To get the latest firmware, run the interface test within VCDS, then press "Config". In the app which opens, select the 'Update' tab, 'Check for Updates', then download and install all updates offered.
Government issued photo ID. (e.g. Passport, Driving License, National ID card, etc.)
This is a requirement of VW. You will need it to create an SFD Service account with Ross-Tech here.
Ross-Tech will not keep the photographic copy of the ID document itself, but are required by VW to securely store the details of the document (typically document number, issue/expiry date, issuing authority, etc.) for a period of 30 years, so VW have full traceability of system usage.
IMPORTANT - The name on the photo ID must match the name on the SFD Service order AND the name on the VCDS registration, or it will be refused.
Once your SFD Service account has been created, you'll need to create a password within the VCDS Interface Config utility.
An acknowledgement of this will be emailed back to you, with a confirmation password which needs to be entered in VCIConfig, (similar to the way the interface registration is confirmed with a transaction ID).

How much will it cost?

Ross-Tech reluctantly have to charge for SFD access, to cover the charges VW levy against them for access to the system.
The cost for accessing the SFD service depends on the type of interface license you have.
Should you have no requirement to use SFD yet (such as no 2020 or newer cars), you do not need to sign up, until such time as that changes.

Owners of VIN Limited interfaces (i.e. 3-VIN or 10-VIN units) will need to pay $50 USD per year, direct to Ross-Tech, via the SFD Service page.
Owners of Unlimited VIN interfaces will have to pay $100 USD per year, via the same page.
There is an exception to this, for owners of Unlimited VIN interfaces, who purchased them (new, not 2nd-hand) on or after January 1st 2023.
This was the date that Unlimited VIN interfaces increased in price by approx $50 USD, to cover the development costs of SFD. Owners of Unlimited VIN interfaces purchased since that time will get their first year of access for free, which equates to saving of approx. $50 USD overall.

What about SFD2?

There is a lot of confusion and misinforation regarding SFD2.
SFD2 is essentially VW's interpretation of the UNECE Cybersecurity regulations. It mainly applies to cars sold in Europe since 2024.
SFD2 is not designed to totally lock the car out for enthusiasts - the aim is to prevent modification and coding/adaptation changes being made, without legitimate authorisation (to prevent actions such as stealing a car by coding in a new key).

Contrary to popular belief, you do not need an SFD2 tool to maintain a car with SFD2 fitted.
The first generation of SFD was only installed at a system level, so should you wish to perform an EPB pad change, you only had to unlock SFD on the Parking Brake or ABS controller (depending on the type of vehicle).
SFD2 requires you to unlock the vehicle's CAN Gateway first.
Once you're past the gateway, the systems required for general servicing and maintenance can still be unlocked via SFD (SFD1).

So what's all the fuss about? UNECE / SFD2 prevents a lot of the tweaks and changes that VAG owners have become used to being able to do, such as disabling seatbelt chimes, enabling special modes on the dials or infotainment, retrofitting cruise control or a towbar etc.
Coding and adaptation is only allowed on SFD2 protected vehicles where it is required for a service/maintenance function.

Which models are known to be affected?

From the 2020 model year on, vehicles based on the MQB2020, MQBevo and MEB platforms are known to have SFD.
This list is not exhaustive though; other new models will also be affected:

MQBevo / MQB2020 Platforms

Audi A3/S3 Mk4 (2020-on)
Audi Q6 (2022-on)
Cupra Formentor (2021-on)
Ford Tourneo/Transit Connect Mk3 (2022-on)
SEAT Leon Mk4 (2020-on)
Skoda Superb Mk4 (2023-on)
Skoda Octavia Mk4 (2020-on)
Volkswagen Caddy Mk4 (2020-on)
Volkswagen Golf Mk8 (2019-on)
Volkswagen Lamando L (2022-on)
Volkswagen Multivan (T7) (2022-on
Volkswagen Passat (B9) (2023-on)
Volkswagen Talagon (2021-on)
Volkswagen Tavendor (2022-on)
Volkswagen Tiguan Mk3 (2023-on)

MEB Platform

Audi Q4 e-tron (2021-on)
Audi Q4 Sportback e-tron (2021-on)
Audi Q5 e-tron (2021-on)
Cupra Born (2021-on)
Cupra Tavascan (2023-on)
Ford Explorer EV (2024-on)
Skoda Enyaq (2020-on)
Volkswagen ID.3 (2019-on)
Volkswagen ID.4 (2020-on)
Volkswagen ID.5 (2021-on)
Volkswagen ID.6 (2021-on)
Volkswagen ID.7 (2023-on)
Volkswagen ID. Buzz (2022-on)

Any new / updated / face-lifted VAG model from 2020 onwards is likely to have the SFD system fitted.

Additionally, the following models are known to have SFD2: