VESPA GTV 125, Service Station Manual

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Example with programmed control unit, trans-
ponder, programmed key and aerial working prop-
erly.
Ignition is enabled (regular conditions of use)
Ignition circuit
Once the immobilizer system is enabled, the HV coil and the signals from the Pick-Up will produce a
spark in the spark plug.
The battery provides the basic power supply. The system is adjusted so that the start-up system im-
mediately detects an eventual battery voltage drop, but this is practically irrelevant for the ignition
system.
The Pick-Up is connected to the control unit by a single cable; then, for the ground circuit, the control
unit is connected to the Pick-Up by the chassis and the engine ground lead.
To avoid disturbances in the ignition system during start-up, it is very important that the engine-chassis
ground connection bonding is efficient.
No spark plug
Once the lack of power to the spark plug has been detected and the LED indicates it can be ignited,
follow this procedure:
- Pick-Up check.
Disconnect the control unit connector and check that the cable between terminal No. 2 (Green) and
terminal No. 8 (Black) is not interrupted. Check the Pick-Up and its power line:
Electric characteristic
Pick-up resistance value
Pick-up resistance value: 105 ÷ 124 Ohm
If a break in the circuit is found, check again the
flywheel and the engine ground connectors (see
engine manual). If non-conforming values are
measured, replace the Pick-Up; otherwise, repair
the cable harness.
In case conforming values are measured, try re-
placing the control unit (without programming) and
make sure the failure has been solved by checking
sparks are produced in the spark plug; only then
program the control unit.
Vespa GTV 125
Electrical system
ELE SYS - 13