Yamaha WR450F 2021 Owner's Service Manual page 331

TIP
When connected to Yamaha diagnostic tool, the vehicle speed signal line between the meter and ECU
is disconnected and "Er_1" is always shown on the meter display.
1. Remove the wire harness coupler "1" (to the multifunction display).
2. Connect the FI diagnostic tool sub-lead.
3. Connect the FI diagnostic tool sub-lead to the Yamaha diagnostic tool.
EWA20450
WARNING
Never connect the sub-lead (special tool) to the battery. Otherwise, because of excessive cur-
rent flow, the sub-lead can catch fire and the battery could be damaged.
TIP
For information on how to connect and use the Yamaha diagnostic tool, refer to "YAMAHA DIAGNO-
STIC TOOL OPERATION MANUAL".
2 2 2
1. Vehicle
2. Wire harness coupler (to the multifunction
display)
3. FI diagnostic tool sub-lead
4. Sub-harness (included with the Yamaha diag-
nostic tool)
5. Vehicle communication cable (included with
the Yamaha diagnostic tool)
6. Yamaha diagnostic tool
1 1
FI diagnostic tool sub–lead
90890-03212
FI diagnostic tool sub–lead
YU-03212
1
2
3
8-32
FUEL INJECTION SYSTEM
6
4 5