PIAGGIO Vespa LX 150 4T Euro 3 Service Station Manual page 68

Electrical system
Whenever the LED is off and remains so, even
when switching it to «ON», it is necessary to check
if:
- the battery is charged
- 15A main fuse is working correctly.
Connect the immobilizer tester to the diagnosis
socket (see ET4 125 manual) located behind the
front left fuse box flap.
If the serial LED remains off, check the electronic
control unit supply as follows:
- Disconnect the control unit connector and check
if:
- There is battery voltage between terminal 8 (Red/
Blue) and the ground lead.
- There is battery voltage between the terminal 8
(Red/Blue) and the terminal 12 (Black) as shown
in the figure
- there is battery voltage between terminals 9 and
12 with the key switch in «ON».
If no faults are found, replace the control unit.
Virgin circuit
If the ignition system has not been programmed,
the engine can be started but it will run limited to
2000 rpm. When trying to accelerate, some evi-
dent loss of power may be felt.
Program the system with the MASTER (Brown)
and SERVICE (Blue) keys as follows:
- Insert the MASTER key, turn it to "ON" and keep
it in that position for 2 seconds (limit values: 1 ÷ 3
seconds).
ELE SYS - 18
Vespa LX 125 - 150 4T Euro 3