Gilera 633721 Workshop Manual page 271

Nexus 500 euro 3
Pressure sensor
This sensor does not have a system since it is di-
rectly installed into the control unit.
The sensor allows the control unit to optimise the
engine performance based on altimetric varia-
tions.
To check the sensor, proceed as follows:
1 - Connect the diagnostic tester.
Select the function "ERRORS" in the menu.
Check whether there are any indications regarding
the pressure sensor.
YES go to 2 NO go to 3
Specific tooling
020460Y Scooter diagnosis and tester
2 - Replace the injection control unit.
3 - Select the menu on the "PARAMETERS" function.
Check that the pressure value in mm/Hg matches that of another scooter or of an external barometer.
Electric characteristic
Max error:
± 20 mmHg
YES go to 4 NO go to 5
4 - The ambient pressure signal is correct.
5 - Replace the injection control unit.
Throttle valve opening sensor
Throttle position sensor (t.p.s.)
Electric characteristic
TERMINALS: 1 - 22
CONDITIONS: Switch set to "ON"
Injection
INJEC - 271