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/InstallationFront Wheel Rotation Sensor Signal (Service Code 27)
Front Wheel Rotation Sensor Signal Inspection
The front wheel rotation sensor sends the signal to the
ECU through the KIBS hydraulic unit (KIBS equipped
models). For other than KIBS equipped models, the
signal is sent directly to the ECU.
The ECU uses the wheel rotation sensor signal for KTRC
...
Ignition Switch/Steering Lock
This is a three-position, key-operated
switch. The key can be removed from
the switch when it is in the OFF or
LOCK position.
A. Ignition Switch/Steering Lock
B. ON position
C. OFF position
D. LOCK position
NOTE
The tail, city and license plate lights
are on whenever the ignition key i ...
Exhaust Butterfly Valve Actuator Sensor Output Voltage Inspection
NOTE
Before this inspection, confirm the pulley is original
position (see Exhaust Butterfly Valve Actuator Installation).
Disconnect:
3 Pins Connector [A] (see Exhaust Butterfly Valve Actuator
Sensor Output Voltage Inspection)
2 Pins Connector [B]
Connect the harness adapter [A ...