APRILIA SR MAX 125 ie Service Station Manual page 160

Injection
- 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 rpm-timing 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 diagnostic 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
020680Y Diagnosis Tool
The MIU injection-ignition system carries out
checks on the rpm indicator and the electric fan for
radiator cooling.
The MIU control unit has a decoder for the anti-
theft immobilizer system.
The MIU control unit is connected to a diagnostic
LED on the instrument panel, that also carries out
the deterrent flashing functions.
The MIU control unit power supply is furthermore controlled by the emergency switch; that is to provide
further safety for the vehicle.
INJEC - 160
SR MAX 125 ie