VESPA 946 E4 EMEA 2021 Manual page 124

Electrical system
COIL
Function
Allows generation of the electrical discharge on
the spark plug, with an increase of voltage.
Pin-out:
1. Activation by control unit (control unit side PIN
1)
2. Relay powered (PIN 87 relay side)
ELECTRICAL ERRORS
H.V. Coil P0351 - shorted to positive / open circuit or short-circuit to negative.
Error cause
Short-circuit to positive: excessive voltage at PIN 1 of the control unit connector.
Open circuit or short-circuit to negative: interruption of the circuit or null voltage at PIN 1 of the control
unit connector.
Troubleshooting
Short-circuit to positive:
- Disconnect the coil connector, turn the key to ON and activate the component through the diagnostic
tool.
- Verify the presence of voltage on the coil connector PIN 1: if present, restore the cabling, otherwise
replace the coil.
Open circuit:
- Carry out the check procedure of the coil and control unit connectors.
- Verify continuity of the wiring harness between the coil and control unit: Coil PIN 1 - control unit PIN
1. If there is no continuity, restore the wiring harness.
- Verify, with the key turned ON, the presence of voltage on the coil connector PIN 2:. If no voltage is
read, verify the continuity of the cabling between coil and injection relay (No. 35 on the electrical circuit
diagram): Coil PIN 2 - relay PIN 87.
- If the above tests provided a positive result, the coil should be replaced.
Short-circuit to negative:
- Disconnect the control unit connector and the coil connector.
- Verify the coil connector PIN 1 ground insulation (or control unit connector PIN 1). Repair the wiring
harness if necessary.
ELE SYS - 124
Vespa 946 E4-E5 EMEA-USA-ASIA (2021-)