NOTE
Be sure the battery is fully charged.

Main Harness [B] Oxygen Sensor [C]
Special Tool - Measuring Adapter: 57001-1700
Oxygen Sensor Heater Power Source Voltage Connections to Adapter: Digital Meter (+) → R (main harness W/R) lead Digital Meter (–) → Frame Ground terminal

Power Source Voltage Standard: Battery Voltage
If the reading is in specification, but the problem still exists, replace the ECU (see ECU Removal/Installation in the Fuel System (DFI) chapter).
If the reading is out of the standard, check the following.
ECU Relay Fuse 15 A (see Fuse Inspection in the Electrical System chapter) Power Source Wiring (see Oxygen Sensor Circuit)
If the fuse and wiring are good, remove the ECU and check the wiring for continuity between harness connectors.
Special Tool - Hand Tester: 57001-1394
Disconnect the ECU and sensor connectors.

Wiring Continuity Inspection ECU Connector [A] ←→ Oxygen Sensor Connectors [B] R lead (ECU terminal 76) [C]
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).
Oxygen Sensor Circuit

1. ECU
2. Oxygen Sensor
3. Ignition Switch
4. Joint Connector F
5. Joint Connector A
6. Fuse Box 1
7. Ignition Fuse 15 A
8. Relay Box
9. ECU Main Relay
10. Frame Ground 3
11. Starter Relay
12. ECU Fuse 15 A
13. Main Fuse 30 A
14. Battery
15. Engine Ground
Oxygen Sensor Heater Resistance Inspection
KIBS Hydraulic Unit Communication Error (Service Code 1b, KIBS Equipped
Models)Crankcase Splitting
Remove the engine (see Engine Removal in the Engine
Removal/Installation chapter).
Set the engine on a clean surface and hold the engine
steady while parts are being removed.
Remove:
Cylinder Head (see Cylinder Head Removal in the Engine
Top End chapter)
Starter Motor (see Starter M ...
Air Cleaner Housing Removal
Remove the fuel tank (see Fuel Tank Removal).
Disconnect the secondary fuel hose [A] from the delivery
pipe of the nozzle assy [B] (see Fuel Hose Replacement
in the Periodic Maintenance chapter).
Disconnect the secondary fuel injector connectors [C].
Free the lead from the grooves [D].
...
Steering Stem Warp Inspection
Whenever the steering stem is removed, or if the steering
can not be adjusted for smooth action, check the steering
stem for straightness.
If the steering stem [A] is bent, replace the steering stem.
Stem Cap Deterioration, Damage Inspection
Replace the stem cap if its oil seal [A] s ...