PIAGGIO 500 cc Service Manual page 154

Fuel injection
The control unit reveals an anomaly on the wire of pin 19
YES
Earth wire
In this case the pump
turns constantly when
under-panel tension is
present.
Check and reset the
earthing isolation of wires
19-85 (of the electromag-
netic switch). Check the
two sections separately:
vehicle system fuel
injection system
Cancel the code and
check from the beginning
9 - 42
Broken wire connection
The relay cannot control the
pump feed.
Install special tool 020481Y between the control unit
and fuel injection system - see page 9-8.
Set to "ON" with the switch set to "RUN" and side
stand raised.
Wait more than 2 seconds and check the following
conditions:
19-23 = battery tension
NO
Replace the control unit
YES
YES