A power increase (for example an ECU remap) on a car needs document (1) or (2).
Inspection neededYes
Certified part neededYes
What you need to know
Document (1) or (2) is required.
Document (1): report from an approved technical service on the compliance of the modifications with the legal framework (individual approval).
Document (2): conversion certificate from an automotive professional with the chassis number, a precise description of the modifications and references to the technical reports (TÜV, Gutachten) of the parts, plus copies of those reports.
A combination of modifications that influence each other (for example wheels and suspension, spacers and suspension, power and wheels) always needs document (1).
The SNCA page lists power increase for cars (M1) and motorcycles (L); it does not mention ECU remaps separately.
The check must happen before the vehicle goes back on the road, or at the latest before the next technical inspection and never more than 2 months after the modification.
If the change is not entered in the 'remarques' field of the registration certificate, the inspection records a major defect.
If the documents are incomplete, the vehicle must go to an approved technical service for a compliance report.