APRILIA 854239, Service Station Manual

Page: 59 / 216

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shorted to negative: disconnect the sensor connector and check ground insulation of the
orange cable (from throttle sensor connector or control unit connector): if there is continuity
with the ground connection, restore the cable harness; if insulated from ground connection,
the resistance between PIN 1 and PIN 2 is below 1.3 kOhm; therefore, replace the throttle
body.
throttle sensor 123 - open circuit, shorted to positive.
Error cause
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If the circuit is open, shorted to positive: excessive voltage has been detected at PIN C3 of
the control unit connector.
Troubleshooting
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Circuit is open, shorted to positive: check the injection control unit connector and the sensor
connector: if they are not OK, restore; if they are OK, check continuity between PIN C3 of
the control unit connector and PIN 2 of the sensor (orange cable): if there is no continuity,
restore the cable harness; if there is continuity, check continuity of the sensor between PIN
1 and PIN 2: if there is no continuity, replace the potentiometer; if there is continuity, check
the resistance. If resistance is over 4.3 kOhm, it will indicate that the orange cable is shorted
to positive and the cable harness should be restored.
adjustable parameters:
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Throttle position self-learning: it allows the control unit to detect the closed and open throttle
position: just press the enter button. This must be done in case the potentiometer throttle
body, the throttle body or the injection control unit have to be replaced.
Reset procedure:
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Once the throttle body or the injection control unit is replaced, it is necessary to connect to
the diagnosis instrument selecting FUEL INJECTION and carry out the operation: Throttle
self-learning, min. position / Throttle self-learning, max. position.
Engine temperature sensor
Function
indicates the engine temperature to the control unit so as to optimise carburetion and idle control
MXV 450
Electrical system
ELE SYS - 59