Fiat 1996 Brava Service Manual page 329

Bravo ijgl 20v
98 range
1. Rpm sensor
2. Toothed pulley
3. Engine flywheel
Engine
Fuel system
10.
RPM AND TDC SENSOR
(0.261.210.160)
This sensor which detects the engine speed
and TDC is the inductive type, i.e. it operates
through the variation of the magnetic field
produced by the passing of the teeth on a
toothed pulley (flywheel) inside the cylinder
block/crankcase fixed to the crankshaft rear
counter-weight. In this way the sensor is
fixed to the cylinder block/crankcase and the
gap and the angular position no longer need
to be checked or adjusted.
The teeth which pass in front of the sensor al­
ter the gap between the pulley and the sen­
sor; the flow, which varies as a result, pro­
duces an alternating voltage whose frequen­
cy depends on the number of revs.
The flywheel consists of 58 teeth plus a
space equivalent to the size of the two miss­
ing teeth.
The reference defined by the space of the two
missing teeth constitutes the basis for detect­
ing the synchronism point (TDC).
Removing-refitting
Position the vehicle on a lift, then, working
from the lower part of the vehicle:
- disconnect the electrical connector;
- undo the bolt fixing the sensor and remove
it from its housing.
Wiring connector
The sensor is connected to the electronic
control unit (pins M10 and M59) by twisted
cables covered with an anti-interference out­
er casing.
The numbers indicate the corresponding
control unit pins
Checking the resistance
The sensor resistance can be measured by
disconnecting the connector and connecting
an ohmmeter to the sensor.
Resistance: 774-946 ohm at 20°C
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