VESPA GTV 250 i.e. 2008 Service Station Manual page 182

Injection
With the interface cable harness disconnected
from the control unit, check continuity between pin
13 and the red cable of the engine speed sensor
connector and between pin 15 and the brown ca-
ble of the engine speed sensor connector
With the interface wiring and rpm sensor connec-
tor disconnected from the control unit, check that
the Red and Brown cables (pin 13 - 15) are isola-
ted from each other and insulated from the ground.
Specific tooling
020481Y Wiring of the control unit's interface
020331Y Digital multimeter
INJEC - 182
Vespa GTV 250 i.e.