It looks like Revo are being more honest and up front where TD1 is concerned..
Taken from their site
Have you read this from Revo site ........IS REVO SOFTWARE UNDETECTABLE? SALES SUPPORT
By law, Revo and our Authorised Dealers have to inform you that you are making a modification to your vehicle. This modification should be declared to insurance companies. There are modification friendly insurance companies out there, just keep looking.
The long and short answer is 'No, Revo software is not undetectable'.
On first glance, there is no reason for your dealer to realise that your engines ECU has Revo Software flashed. Revo create all of our software from full factory software, and write an entire software file to the ECU, as opposed to “data area” files used by other tuners.
As the ECU will ID, DTC check, and function as it would with factory software, switched to Stock Mode using an SPS it is virtually undetectable by the main dealer. Dealer tools are constantly evolving to incorporate new technology, there is always a possibility that main dealer tools could see that an ECU has been modified and isn’t stock.
If of course the dealer drives the vehicle in performance mode it will be obvious to the driver that the car has been modified. This could be confirmed by data logging the car and seeing that certain requested ECU parameters are higher than expected for a standard vehicle. The long and short of it is we cannot guaranty the software will go un-noticed by the main dealer.
NOTE: As of 2013, the VW Group online dealer tools have the ability to see software on any modified vehicle. When a modified vehicle is plugged in online it is flagged on the system, this flag is called TD1 please read the below overview:
TD1is the VW Audi Group warranty ‘Flag’ for a vehicle that has been modified, this is something you should all be well aware of. If you’re not then please note; since the change in main dealer on-line diagnostic tools throughout 2013 performance software can and will be seen when a vehicle is plugged into online at a main dealer. This is the case even if it’s switched to ‘stock’ mode, it is possible although not confirmed that TD1 could be flagged if a vehicle has been flashed with any tool other than the OEM online system. Our recommendation to all our dealers is to make the vehicle owner aware that their warranty will be affected if they have software installed on their vehicle; this isn’t anything new as we’ve never claimed software is undetectable however prior to the new main dealer systems Revo software did tend to go unnoticed.
