Yamaha YZ450F 2020 Owner's Service Manual page 291

9. Check the stator coil assembly.
Refer to "CHECKING THE STA-
TOR COIL" on page 8-48.
OK
10.Check the ignition system wire har-
ness.
Refer to "CIRCUIT DIAGRAM" on
page 8-1.
OK
Replace the ECU.
The launch control indicator light fail to blink.
TIP
Before troubleshooting, remove the following part(s):
1. Seat
2. Air scoop (left)
1. Check the launch control switch
coupler connections.
OK
2. Check the gear position switch cou-
pler connections.
OK
3. Check the launch control switch.
Refer to "CHECKING THE
SWITCHES" on page 8-41.
OK
4. Check the gear position switch.
Refer to "CHECKING THE GEAR
POSITION SWITCH" on page 8-51.
OK
5. Check the fuel ignition system wire
harness.
Refer to "CIRCUIT DIAGRAM" on
page 8-1.
OK
Replace the ECU.
Replace the stator coil assembly.
NG
Repair or replace the wire harness.
NG
Reconnect.
NG
Reconnect.
NG
Replace the launch control switch.
NG
Replace the gear position switch.
NG
Repair or replace the wire harness.
NG
8-4
IGNITION SYSTEM