Gilera 633721, Workshop Manual

Page: 248 / 407

CIRCUIT LAYOUT
Specification Desc./Quantity
1 Electronic control unit
2 Engine rpm sensor
The sensor allows the rotations and the angular position of the crankshaft to be recognised by reference
to the TDC. Since the wheel speed sensor is pivoted on the camshaft it is also possible to recognise
the 4-stroke cycle. Such solution allows controlling the injector and the spark plug every two revolutions
of the crankshaft.
The sensor is of the reluctance variation type and is therefore comparable to an alternate current gen-
erator that powers the control unit.
The signal frequency is interrupted by the vacuum generated by the two missing teeth on the wheel
speed sensor.
The sensor signal is fundamental for obtaining starting of the engine.
The ECU self-diagnosis is enabled on this circuit in 2 different ways based on use conditions.
Right after turning to « ON » (Power under the panel present in the CPU), the continuity and isolation of
the sensor and related circuit are checked.
Any faults discovered in this phase are signalled via the injection telltale light.
Injection
Nexus 500 euro 3
INJEC - 248