PIAGGIO 500 cc Service Manual page 141

Using the special tool check the
basic feed of the control unit
PIN 17= positive battery
PIN 23= negative battery
YES
Control unit basic feed
is correct
If lack of the battery negative is revealed, check the harness and earthing to the control unit clamp.
If lack of the battery positive is revealed,
disconnect the connection between the fuel
injection system and the vehicle system.
The vehicle system is recognizable by the
connector with a coupling control button.
Red-white wire on the connector,
vehicle system side = battery positive
Red-white wire, fuel injection system side =
continuity with PIN 17 of the tool and n° 3 of
the decoder.
NO
YES
Fuel injection
NO
NO
Reset the harness
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