Manifold Air Pressure Sensor; Ambient Air Pressure Sensor; Throttle Valve Sensor; Sensor For The 2Nd Throttle Valve - KTM 990 Adventure Repair Manual

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Manifold air pressure sensor

The manifold air pressure sensors are mounted on the frame and
connected to the intake port under the throttle valve with equally long
vacuum hoses. Reducing jets with a 1 mm air hole are connected to
the intake port.
NOTE: If the vacuum hoses are damaged, they must be replaced with
new, original KTM hoses.
!
– A
LWAYS REPLACE THE VACUUM HOSES ON THE INTAKE MANIFOLD IF THEY WERE
.
PULLED OFF
– D
O NOT USE SILICONE SPRAY WHEN MOUNTING THE VACUUM HOSES
DAMAGE THE MANIFOLD AIR PRESSURE SENSORS
– D
O NOT EXCHANGE THE CONNECTIONS ON THE INTAKE MANIFOLD WITH THE
CONNECTIONS ON THE CARBURATOR MODELS OTHERWISE THE INJECTION SYSTEM
.
IS LIKELY TO MALFUNCTION
The intake pressure sensors convert the applied vacuum into an
electric signal for the control unit.
Each of the two intake pressure sensors is supplied with a 5-volt
operating voltage and a ground from the control unit.
The output signal increases with the pressure; i.e. the intake pressure
sensor emits a low voltage signal when the throttle valve is closed and
the pressure in the induction manifold is low (high vacuum due to the
engine's suction effect).
When the throttle valve is completely open, the induction manifold
pressure is practically equivalent to the ambient air pressure and the
voltage signal has a high value.
The sensors must be mounted vertically and the hoses leading to the
sensor inclining (due to condensate formation).

Ambient air pressure sensor

The mode of action is similar to the manifold air pressure sensor.
Information is relayed to the control unit indicating under which
ambient pressure (at which altitude) the vehicle is being driven.
Installed position: under the headlight mask; a 5-cm hose is connected
to the sensor to prevent splashed water from penetrating.

Throttle valve sensor

The throttle valve sensor
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shaft of the front throttle valve and operates like a variable resistor. The
control unit determines the position of the throttle valve based on the
output voltage.
The information acquired is required for the acceleration enrichment,
full-load enrichment, ignition timing and trailing throttle fuel cutoff.

Sensor for the 2nd throttle valve

Operates in the same manner as the throttle valve sensor but is
mounted on the shaft of the rear 2nd throttle valve
the control unit controls the power development.
CAUTION
.
is mounted on the side of the throttle valve
2
!
. I
T CAN
through which