VESPA GTV 125, Service Station Manual

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When the key switch is turned to "ON", it interrupts
the function of the immobiliser lamp and a start
enable lamp comes "ON".
The duration of the flash depends on the electronic
control unit program (see figure).
In case the LED turns off and remains so even
when switching over to "ON", check if:
- there is voltage in the battery - the 15A main fuse
(No. 7) is in working order.
If the deterring LED remains off, check the control
unit power supply as follows:
- Disconnect the control unit connector and check
if:
- There is battery voltage between terminal No. 4
(Red/Black) and the ground lead.
- There is battery voltage between the terminal No.
4 (Red/Black) and the terminal No. 8 (Negative) as
shown in the figure.
- There is battery voltage between terminals No. 5
and No. 8 with the key switch set to "ON", and the
emergency cut-off switch set to "RUN".
If no faults are found, replace the control unit; oth-
erwise check the wiring and the following compo-
nents:
- Emergency cut-off switch;
- Key switch contacts.
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.
To program the system, besides the emergency
cut-off switch set to "RUN", use the MASTER
(Brown) and SERVICE (Black) keys as follows:
Electrical system
Vespa GTV 125
ELE SYS - 10