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/InstallationRadiator Hose and Pipe Inspection (coolant leak, damage, installation
condition)
The high pressure inside the radiator hose can cause
coolant to leak [A] or the hose to burst if the line is not
properly maintained.
Visually inspect the hoses for signs of deterioration.
Squeeze the hoses. A hose should not be hard and
brittle, nor should it be soft or swollen.
Repl ...
Specifications
Whenever you see the symbols
shown below, heed their instructions!
Always follow safe operating and maintenance
practices.
DANGER
DANGER indicates a hazardous
situation which, if not avoided,
will result in death or serious injury.
WARNINGWARNING indicates a hazardous
situation whi ...
ECU Power Supply Inspection
Remove the upper air cleaner housing (see Air Cleaner
Element Replacement in the Periodic Maintenance chapter).
Visually inspect the ECU connectors.
If the connector is clogged with mud or dust, blow it off
with compressed air.
Remove the ECU (see ECU Removal).
Visually inspect the ...