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/InstallationPiston Ring Thickness Inspection
Measure the piston ring thickness.
Use the micrometer to measure at several points around
the ring.
Piston Ring Thickness
Standard:
Top [A] 0.77 0.79 mm (0.0303
0.0311 in.)
Second [B] 0.78 0.79 mm
(0.0307 0.0311 in.)
Service Limit:
Top 0.70 mm (0.0276 in.)
Second 0.71 mm (0.0280 ...
Cam Wear Inspection
Remove the camshafts (see Camshaft Removal).
Measure the height [A] of each cam with a micrometer.
If the cams are worn down past the service limit, replace
the camshaft.
Cam Height
Standard:
Exhaust 35.043 35.157 mm
(1.3796 1.3841 in.)
Intake 38.243 38.357 mm
(1.5056 1.5101 in. ...
Special Tools and Sealants
Outside Circlip Pliers:
57001-144
Piston Pin Puller Assembly:
57001-910
Piston Ring Compressor Grip:
57001-1095
Piston Ring Compressor Belt, 67
79:
57001-1097
Bearing Driver Set:
57001-1129
Liquid Gasket, TB1216B:
92104-1064
Liquid Gasket, TB1207B:
92104-2068
...