PIAGGIO 500 cc, Service Manual

Page: 199 / 239

Fuel injection
9 - 87
9
Check that the tension measured on pins 11 and 22
corresponds with the tension indicated by the
diagnosis tester set to "parameters".
Replace the control unit.
The TPS and related circuit
conform.
YES
NO
NOTE
The TPS control has been set with voltometer checks in that resistance controls are rather unreliable.
To check the potentiometer of a throttle body it is always advisable to connect it to a vehicle, even if only from an
electrical point of view.
TPS RESET
The throttle body is supplied complete with TPS and is precalibrated.
The precalibration consists in an operation of regulating the minimum throttle opening, to achieve a set air flow under
pre-established reference conditions.
Precalibration introduces an optimum air flow for idling management.
This setting must under no circumstances be tampered with.
The fuel injection system will complete the idling management via the stepper and the spark advance variation.
The throttle body, after precalibration, has the valve open at an angle that can vary according to the working
tolerance of the duct and the valve itself.
The TPS, in turn, may assume different mounting positions. For these reasons the mV of the sensor with throttle
to the minimum can vary from one throttle body to another.
To achieve optimum carburation, especially to the small openings of the throttle, the matching of the throttle body
to the control unit is indispensable, via the procedure defined as TPS reset.
Through this operation we inform the control unit, as a starting point, the mV value corresponding to the
precalibration position. The control unit will recognize this position as an angle of 5.24°.
To reset, proceed as follows.
Connect the diagnosis tester 020460Y. (See page 9-17).
Set ignition to "ON" with switch on "RUN" and side stand raised.
YES