Gilera Nexus 500 Workshop Manual page 257

Nexus 500
Injection
Any faults discovered in this phase are signalled via the injection light.
The fault continues to be signalled, but the circuit is only checked when turning to "ON". Therefore faults
which occur or disappear after turning to "ON" are not acknowledged.
During and after the start phase, the autodiagnosis checks the alternating current produced by the
sensor (synchronisation of the signal panel).
If a signal panel is detected which is not perfectly synchronised, corrective interventions are applied
used to reconstruct the cycle. In this case the autodiagnosis records the number of lost synchronisations
and signals the fault via the injection light.
The light remains on during the period the cycle is reconstructed.
If the revolution timing signal is completely missing due to mechanical faults or lack of magnetic activity,
it will be impossible to start the engine (or it will stop while driving) and the autodiagnosis will not be
able to record any faults.
To check the sensor and related circuit, proceed as follows:
1 - Connect the scooter tester.
Select the function "ERRORS" in the menu.
Check for any faults on the «Signal panel».
YES go to 2 NO go to 3
Specific tooling
020460Y Scooter diagnosis and tester
2 THE FAULT HAS BEEN RECORDED IN MEMORISED STATUS:
The signal panel may be synchronised with possibility of starting. The fault is probably occasional.
N.B.
A NON-CONFORMING SIGNAL PANEL FAULT MAY ALSO BE DETECTED IF THE ENGINE STOPS
AFTER A FAULT INVOLVING IDLING.
INJEC - 65