If the radiator fan relay is normal, check the wiring for continuity, using the wiring diagram in this section.
Special Tool - Hand Tester: 57001-1394
If the wiring is good, check the ECU for its ground and power supply (see ECU Power Supply Inspection in the Fuel System (DFI) chapter).
If the ground and power supply are good, replace the ECU (see ECU Removal/Installation in the Fuel System (DFI) chapter).
Radiator Fan Circuit

1. ECU
2. Fan Motor
3. Ignition Switch
4. Joint Connector F
5. Fuse Box 1
6. Ignition Fuse 15 A
7. Relay Box
8. Fan Relay
9. Frame Ground 3
10. Fuse Box 2
11. Fan Fuse 15 A
12. Starter Relay
13. Main Fuse 30 A
14. Battery
15. Engine Ground
Radiator Fan Relay Removal/InstallationSubthrottle Valve Actuator Inspection
NOTE
Be sure the battery is fully charged.
Remove the air cleaner housing (see Air Cleaner Housing
Removal in the Fuel System (DFI) chapter).
Turn the ignition switch to ON.
Check to see that all the subthrottle valves [A] open and
close smoothly.
Turn the ignition switch to OFF.
I ...
Spring Preload Adjustment
Remove the rear shock absorber from the frame (see
Rear Shock Absorber Removal).
Loosen the locknut and turn out the adjusting nut to free
the spring.
Special Tools - Hook Wrench T=3.2 R37: 57001-1539
Hook Wrench R=35: 57001-1580
To adjust the spring preload, turn in the adjusting n ...
Throttle Control System
Check the throttle grip play each day
before riding the motorcycle, and carry
out maintenance and adjustments in
accordance with the Periodic Maintenance
Chart. Adjust it if necessary.
Throttle Grip
The throttle grip controls the butterfly
valves in the throttle body. If the throttle
grip ha ...