APRILIA ETV mille, Workshop Manual

Page: 131 / 352

ETV mille
FUEL SYSTEM
4 - 10 -
00
Release 00/2004 - 04
Throttle position sensor (4)
Location: throttle body (5).
This sensor is a potentiometer. Throttle position is
determined by comparing output voltage to supply
voltage (rating is 5 V) for greater accuracy.
As the throttle opens, the sensor output voltage
increases in a linear pattern. The throttle provides the
most effective means to control engine operation, as it
determines how much air is let through for the engine to
take in. The position (or angle) of throttle is used to
determine load and tells the system whether the rider is
trying to accelerate or slow down.
Engine temperature sensor (6)
The engine temperature sensor is a negative-resistance
thermistor. This means that sensor resistance decreases
as temperature increases. The sensor is conveniently
located to provide an accurate indication of engine
operating temperature. The EMS compensates for the
varying engine characteristic in the different engine
temperature ranges. This is because an engine needs
varying amounts of fuel depending on whether it is
started up from cold or when already warm.
Intake air temperature sensor
Location: air box (7).
The density of intake air varies with air temperature. This
affects engine useful load and subsequently the amount
of fuel required. An additional adjustment is needed to
minimise the risk of knocking due to hot intake air.
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