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/InstallationWater Temperature Sensor Inspection
Remove the water temperature sensor (see Water Temperature
Sensor Removal/Installation in the Fuel System
(DFI) chapter).
Suspend the sensor [A] in a container of coolant so that
the temperature-sensing projection [C] is submerged.
Suspend an accurate thermometer [B] with temperature
...
Cable, Wire, and Hose Routing
1. Clamp (Hold the regulator/rectifier lead. Run the lead inside of the
installation hole.)
2. Clamp (Bend down the clamp, and hold the main harness and the vacuum hose
(equipped
models).)
3. Clamp (Hold the air intake solenoid valve lead (equipped models).)
4. Run the vacuum hose under ...
Relay Circuit Inspection
Remove the relay box (see Relay Box Removal).
Check conductivity of the following numbered terminals
by connecting the hand tester and one 12 V battery to the
relay box as shown in the figure (see Relay Box Internal
Circuit in this section).
If the tester does not read as specified, re ...