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Retrofitting Support

Due to the volume of retrofitting requests we have added the following to the Technical Support Policy for common retrofitting scenarios. If you've installed a part that is not an identical replacement for a part that was installed in your car from the factory, please post your question on a forum , preferably Ross-Tech's own Retrofitting Forum , so that others may contribute to the answers and benefit in the future.

These instructions may not cover mechanical/electronic details, they will only list the the diagnostic side (coding etc.). Additional details for the mechanical/electronic work needed are part of the retrofitting instructions provided by the parts supplier (i.e. trailer hitch retrofits) or can be found in the factory repair manuals and wiring diagrams.

VCDS will communicate with and perform basic scan tool functions on OE (original equipment) VW, Audi, Seat and Skoda control modules that support diagnosis. When it comes to retrofitting components the level of support we provide may be limited. Support is only available to registered users.

Retrofitting Policy

If you install control modules that could have been factory installed in the vehicle from we should be able to help. This is assuming the following conditions are met:

  • The retrofitted module is compatible with the vehicle platform and the remaining modules in the vehicle.

  • The vendors instructions were used to properly:

    • Install the control module(s).
    • Install the needed wiring.
    • Hardware (when needed) for the functionality of the new module is properly installed.

  • The repair manual and wiring diagrams were used to troubleshoot unforeseen problems.

  • The retrofitted module will communicate properly with VCDS.
  • The retrofit in its entirety must comply with legal or OE standards as if it was factory installed. This includes, but is not limited to, Xenon headlights. Aftermarket "Plug-and -Play" systems are rarely legal and do not include the necessary control modules and sensors to complete a proper OE style retrofit. See: AFS Xenon / HID Headlight Retrofitting Policy

Make sure that the following details are included in your email:

  1. Complete Auto-Scans from the vehicle (prior to any modifications and after the new parts have been installed).
  2. Which parts have been installed and the source of those parts (for example new or used, dealer or aftermarket, etc.)?
  3. What are the part numbers and/or manufacturers of the newly fitted components?
  4. Which specific symptoms are being exhibited by the vehicle?

Software Version Management (SVM)

Software Version Management (SVM) is a system used by VW/Audi to update control modules and in certain cases, to change their Coding.

Retrofits and Modifications which are not or cannot documented using Software Version Managements (SVM) at the dealership should be documented in the customer’s vehicle documents. Examples including: Non official retrofit procedures, or ones that aren’t in the VW/Audi system.

We recommend you add the following information to the service/owners manual of the car:

  • Type and complexity of the Retrofitting/Modification
  • Location of the Retrofitting/Modification (Contact Person in Case of Problems)
  • Software/Hardware Part Numbers of the Modules which have been replaced (if applicable)
  • Coding and Adaptation Changes made during the Retrofitting/Modification (before and after)

The Reason for these suggestions is that the dealer tech may perform a SVM Comparison the next time the car comes in. Every discrepancy compared to the settings after the car was produced will be flagged and the tech will be asked he wants to correct those. If he does all changes get reversed and your retrofitting/modification may not work any longer, so the documentation should inform the tech or at least help to reverse the changes made when necessary.

Compatibility