VESPA GTS 250 I.E. Workshop Manual page 209

Vespa GTS 250 I.E.
Injection
Connect the diagnostic tester.
Turn to "ON".
Select the functions of the diagnostic tester on
"TPS RESET".
Specific tooling
020460Y Scooter diagnosis and tester
Make sure that the throttle valve is supporting the
stop screw.
Guaranteeing that this position will be kept, give
the confirmation for the TPS reset procedure.
INJEC - 45