Fiat 1998 Marea Weekend, Service Manual

Page: 177 / 846

Marea-Marea Weekend^
1998 range
16v
Engine
Fuel system
10.
VEHICLE SPEED SENSOR
(SOGECO)
The sensor is located on the differential out-
put, near the left half-axle joint. It sends in-
formation on vehicle speed to the control
unit: the signal is also used to operate the
speedometer.
The sensor operates on the principle of the
Hall effect (see section on "engine timing
sensor") and transmits 16 pulses/revolution.
Vehicle speed can therefore be calculated
from pulse frequency.
Removing - refitting
Disconnect electrical connection and remove
the sensor.
Tightening torque 0.8 daNm
Wiring diagram
SAFETY AND VENTILATION VALVE
This valve is located in the fuel filler cap and
performs the following functions according
to the pressure level in the tank:
- When the pressure inside the tank exceeds
0.13 - 0.18 bar, excess fuel vapours are
vented to the outside (pressure-relief func-
tion).
- If, on the other hand, a vacuum builds up
inside the tank, equivalent to 0.020 - 0.030
bar, air is taken into the tank (ventilation
function).
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