VESPA GTV 250 i.e. 2008 Service Station Manual page 158

Injection
2 MIU system failure may be caused by loose connectors. Make sure that all connections have been
correctly made.
Check the connectors taking into consideration the following point:
A check that the terminals are not bent.
B check that the connectors have been properly connected.
C - Check whether the malfunction can be fixed by shaking the connector slightly.
3 Check the entire system before replacing the MIUIf the fault is fixed by replacing the MIU control unit,
install the original control unit again and check if the fault occurs again.
4 For troubleshooting, use a multimeter with an internal resistance of more than 10 KW/V. Unsuitable
instruments can damage the MIU ECU. The instruments to be preferred have a definition over 0.1V and
0.5W and an accuracy over 2%.
1. Before repairing any part of the injection system, check if any faults have been stored. Do not dis-
connect the battery before checking for faults.
2. The supply system is pressurised at 250 kPa (2.5 BAR). Before disconnecting the fast-release fitting
of the fuel supply pipe, check that there are no naked flames. Do not smoke. Act with caution to avoid
spraying fuel to your eyes.
3. When repairing electric components, the battery must always be disconnected unless it is strictly
necessary for the battery to be connected.
4. When functional checks are performed, make sure that the battery voltage exceeds 12V.
5. Before attempting to start the vehicle, ensure that there are at least two litres of fuel in the tank.
Failure to respect this norm will damage the fuel pump.
6. If a long period is envisaged with the vehicle not in use, fill the tank to at least the halfway mark. This
will ensure the pump will be covered by fuel.
7. When washing the vehicle, do not spray excessive water on electric components and wiring har-
nesses.
8. In the event of ignition problems, begin troubleshooting from the battery and the injection system
connections.
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 poles when fitting the battery.
11. In order to not cause damage, disconnect and reconnect the connectors of the MIU system only
after proven necessary. 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.
INJEC - 158
Vespa GTV 250 i.e.