PIAGGIO 633929(IT), Service Station Manual, Page: 72 / 314

When the key switch is turned to "ON", this blinking
function is deactivated. A flash then confirms the
system has switched to "ON".
The duration of the flash depends on the electronic
control unit program (see figure).
If the led turns off and remains so when switching
to "ON", it is necessary to check if there is battery
voltage in the electric control unit.
Connect the immobilizer tester to the diagnosis
socket (see ET4 125 manual) located below the
spark plug inspection port.
If the serial led remains off, check the control unit
voltage supply; in order to do this, disconnect the
control unit connector and check if:
- there is battery voltage between the terminal No.
6 (Red/Green) and the ground connection.
- there is battery voltage between the terminal No.
6 (Red/Green) and the terminal No. 9 (Negative)
as shown in the figure.
If no voltage is detected, check the wiring to the
battery positive lead and see if 15A fuse No. 4 is
in good conditions.
- there is battery voltage between the terminal No.
8 (Orange) and the terminal No. 9 (Negative) with
the key switch set to "ON" and the emergency
switch set to "RUN".
If no faults are found, replace the control unit; oth-
erwise check the wiring and the following compo-
nents:
- Engine stop remote control;
- Emergency cut-off switch;
- Key switch contacts.
Electrical system
MP3 125
ELE SYS - 12