PIAGGIO Vespa LX 150 4T Euro 3 Service Station Manual page 72

Electrical system
- HV primary coil check
Disconnect the control unit connector and check
that the cable between terminal No. 4 (violet) and
terminal No. 12 (black) is not interrupted (see fig-
ure).
If non-conforming values are measured, check
again the HV coil primary directly on the positive
and negative terminals.
If the values are correct, repair the cable harness
or reset the connections; otherwise, replace the
HV coil
Electric characteristic
High voltage coil primary resistance value
High voltage coil primary resistance value: 0.4 ÷
0.5 Ohm
- HV coil secondary check
Disconnect the spark plug cap from the HV cable and measure the resistance between the HV cable
terminal and the HV coil negative terminal (see figure).
If non-conforming values are measured, replace the HV coil. To carry out a more complete diagnosis,
check the peak voltage with the multimeter adaptor.
Specific tooling
020409Y Multimeter adaptor - Peak voltage detection
Electric characteristic
High voltage coil secondary resistance value
High voltage coil secondary resistance value: ~ 3000 ± 300 Ohm
ELE SYS - 22
Vespa LX 125 - 150 4T Euro 3