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/InstallationSelf-Diagnosis Procedures
NOTE
Use a fully charged battery when conducting
self-diagnosis. Otherwise, the light (LED) and symbol
do not light or blink.
Turn the ignition switch to ON.
When a problem occurs with DFI system and ignition system,
the warning indicator light (LED) [A] goes on and
FI warning symbol ...
Intake Air Temperature Sensor Removal
NOTICE
Never drop the intake air temperature sensor especially
on a hard surface. Such a shock to the sensor
can damage it.
Remove the fuel tank (see Fuel Tank Removal in the Fuel
System (DFI) chapter).
Disconnect the connector [A] from the intake air temperature
sensor.
Remove the da ...
Oxygen Sensor - not activated (Service Code 33, Equipped Models)
Oxygen Sensor Removal/Installation
Refer to the Oxygen Sensor Removal/Installation
(Equipped Models) in the Electrical System chapter.
Oxygen Sensor Inspection
Remove:
Fuel Tank (see Fuel Tank Removal in the Fuel System
(DFI) chapter)
Oxygen Sensor Lead Connector [A]
Connect t ...