Troubleshooting Hints - PIAGGIO MP3 400 i.e. Service Manual

MP3 400 i.e.
Injection
5. Before trying to start up, check to make sure there is at least two litres of fuel in the tank. Failure to
respect this norm will damage the fuel pump.
6. If the scooter is expected to remain unused for a long time, refill the tank up to a little over half the
level. This will ensure the pump will be covered by fuel.
7. When washing the vehicle, be careful with the electric components and wiring.
8. When an ignition fault is detected, start the checks from the battery and the injection system con-
nections.
9. Before disconnecting the MIU control unit connector, perform the following steps in the order shown:
- Set the switch to «OFF»
- Disconnect the battery
Failure to respect this norm may damage the control unit.
10. Do not invert the polarity when fitting the battery.
11. To avoid damage, only disconnect and reconnect the MIU system connectors if required. Before
reconnecting, check that the connectors are dry.
12. When carrying out electric inspections, do not force the tester probes into the connectors. Do not
take measurements not specifically foreseen by the manual.
13. At the end of every check performed with the diagnostic tester, protect the system connector with
its cap. Failure to do this may damage the MIU control unit.
14. Before reconnecting the quick couplers of the power supply system, check that the terminals are
perfectly clean.

Troubleshooting hints

1 A fault in the MIU system could most likely be due to the connections and not the components.
Before troubleshooting the MIU system, carry out the following checks:
A: Electrical power supply
a. Battery voltage
b. Blown fuse
c. Remote controls
d. Connectors
B: Chassis earthing
C: Fuel supply
a. Broken fuel pump
b. Dirty fuel filter
D: Ignition system
a. Faulty spark plug
b. Broken coil
c. Broken shielded cap
E: Intake circuit
a. Dirty air filter
INJEC - 5