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/InstallationExhaust Butterfly Valve Cable Removal
Remove the fuel tank (see Fuel Tank Removal in the Fuel
System (DFI) chapter).
Open the clamp [A] and free the cables.
Slide the dust covers [B].
Loosen the locknuts [A], and turn the adjusters [B] to give
the cable plenty of play.
Remove the clamp [A].
Remove the up ...
Radiator Inspection
Remove the radiator (see Radiator and Radiator Fan Removal).
Check the radiator core.
If there are obstructions to air flow, remove them.
If the corrugated fins [A] are deformed, carefully
straighten them.
If the air passages of the radiator core are blocked more
than 20% by unremovable ...
Terminal Numbers of ECU Connectors
1. Subthrottle Valve Actuator: Y/BK
2. Subthrottle Valve Actuator: BK/O
3. Unused
4. Front Wheel Rotation Sensor Signal: G/Y
5. Unused
6. Starter Lockout Switch: R/G
7. Gear Position Switch: G/R
8. Crankshaft Sensor (–): BK
9. Power Supply to Sensors: BL
10. Unused
11. Intake Air Pre ...