Fiat 1996 Brava Service Manual page 445

Bravo- Brava W
X6v
1998 range
Engine
Fuel system
The following graph shows sensor voltage output
for different throttle opening angles.
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10.
THROTTLE VALVE POSITION SENSOR
A. Sensor used on premodification cars
B. Sensor used on postmodification cars
The sensor consists of a potentiometer with its
mobile part controlled by the throttle valve
spindle.
The potentiometer is enclosed in a plastic
container. In solution A adopted on premodi­
fication models, the potentiometer case is fit­
ted with two tabs. These have two UNSLOT­
TED holes to anchor and position the sensor
in relation to the throttle valve. In solution B
adopted on post-modification cars, the sensor
is integral with the throttle body.
A three-pin socket (ABC) on the container
ensures an electrical connection to the elec­
tronic injection-ignition control unit
During operation, the electronic control unit
supplies the potentiometer with a voltage of 5
Volts. The parameter measured for injection
management is throttle position from idle to
full opening.
The output voltage tells the control unit how
far the throttle valve is opened and it corrects
mixture concentration accordingly.
When the throttle is closed, a voltage signal is
sent to the control unit,which recognises idle
and cut-off (discerning between them on the
basis of engine rpm).
The potentiometer is linear (single ramp type).
Its main features are as follows:
Effective electrical angle: 90° ± 2°
Total mechanical travel: 110° ± 8°
Service temperature range: -30°C - +125°C
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