Gilera 633721 Workshop Manual page 286

Injection
E. Engine Warning indicator light
F. Low fuel warning light
G. Oil warning light
64. Fuel injection electronic control unit
The electric fan system is powered by a remote
control switch connected to the continuous power
supply controlled by the electronic control unit of
the injection system.
The electronic control unit of the injection system
controls the electric fan in relation to the measured
engine temperature.
If prolonged running of the electric fan is noticed,
check the following carefully before starting to
check the electrical system:
- Coolant level in the expansion tank - bleeding of
the inlet hose to the engine
- Bleeding of the outlet from the head
- Function of the thermostat
- Function of the pump
For these checks, see chapter "Cooling system".
To check the circuit, proceed as follows:
1 - Connect the diagnostic tester. Set the switch to
"ON" with switch to "RUN" and side stand raised.
Select the "ERRORS" function. Check whether the
control unit has detected any failures relating to the
electric fan control circuit.
YES go to 8 NO go to 2
2 - Select the menu on the "ACTIVE DIAGNOSIS"
function. Activate the electric fan diagnostic func-
tion. Check acoustically for rotation of the electric
fan. Wait for the exit from the diagnostic tester.
YES go to 3 NO go to 4
INJEC - 286
Nexus 500 euro 3