PIAGGIO 633823 Service Station Manual page 156

Injection
- HV coil
- HV cable
- Shielded cap
- MIU control unit
- Spark plug
The MIU control unit manages ignition with the best advance ensuring four-stroke timing (ignition only
in the compression phase) at the same time.
The MIU injection-ignition system controls engine functions by means of a pre-set program.
Should any input signals fail, an acceptable working order of the engine is ensured to allow the user to
reach a service station.
Of course, this cannot happen when the rev counter signal is missing, or when the failure involves the
control circuits:
- Fuel pump
- HV coil
- Injector
The control unit is provided with a self-diagnosis
system connected to an indicator light in the in-
strument panel.
Failures are detected and restored by the diag-
nostic tester.
In any case, when the fault is no longer present,
the data storage is automatically cleared after 16
cycles of use (cold start, running at regular engine
temperature, stop).
The diagnostic tester is also required to adjust the
idle mixture.
Specific tooling
020460Y Scooter diagnosis and tester
INJEC - 4
MP3 250 i.e.