PIAGGIO MP3 400 i.e., Service Manual, Page: 318 / 394

- Select the menu on the "ACTIVE DIAGNOSIS"
function and start the electric fan operation simu-
lation (see "Injection" chapter).
- If the electric fan is certainly efficient, check the
ventilation start and end temperature.
- Select the "PARAMETERS" function in the menu
to display the coolant temperature.
Electric fan starts: 107°C
Electric fan stops: 103°C
- If non-conforming values are detected, replace
the injection control unit (see «Injection» chapter).
- If the analogue instrument temperature is close
to the red zone, but the degrees indicated by the
diagnostic tester are below the electric fan start
temperature, check the temperature sensor on the
head and the relevant injection circuit (see «Injec-
tion» chapter);
N.B.
THE ELECTRIC FAN TEMPERATURE AT 107° C CAN ONLY BE MANAGED BY A SYSTEM SUP-
PLIED WITH A 50% MIXTURE AND PRESSURISED AT 0.9 BAR.
AVOID STARTING THE ENGINE WITHOUT PRESSURISATION SINCE IT MAY REACH THE BOIL-
ING TEMPERATURE BEFORE THE ELECTRIC FAN STARTS WORKING.
IN CASE OF AN INCREASE OF THE ELECTRIC FAN START TIME, CHECK THE THERMOSTAT
OPENING TEMPERATURE AND CHECK THAT THE COOLANT DENSITY IS CORRECT. THE OP-
TIMUM DENSITY IS OBTAINED WITH A 50% WATER AND 50% COOLING CIRCUIT FLUID
MIXTURE.
System sealing check
- Check the proper circuit sealing when it is in
pressure and at the temperature.
- For a more accurate check, wait until the system
has cooled down since small leaks may not be
visible due to evaporation
- The water pump is provided with a drainage hole
in case of leaks from the cooling system mechan-
ical seal, or from the shaft sealing oil guard.
- If coolant or oil leaks are detected, replace the pump (see «Flywheel Cover» Chapter).
N.B.
Cooling system
MP3 400 i.e.
COOL SYS - 4