Oxygen Sensor Removal/Installation
Refer to the Oxygen Sensor Removal/Installation (Equipped Models) in the Electrical System chapter.
Oxygen Sensor Inspection

Main Harness [B] Oxygen Sensor [C]
Special Tool - Measuring Adapter: 57001-1700

Oxygen Sensor Output Voltage Connections to Adapter: Digital Meter (+) → R (sensor BK) lead Digital Meter (–) → BK (sensor GY) lead

Do not disconnect the air switching valve connector [B].

Air Cleaner Housing (see Air Cleaner Housing Installation in the Fuel System (DFI) chapter) Fuel Tank (see Fuel Tank Installation in the Fuel System (DFI) chapter)

Measuring Adapter [A]
Output Voltage (with Plugs, Rich) Standard: DC 0.8 V or more

| WARNING The engine gets extremely hot during normal operation and can cause serious burns. Never touch a hot engine. |

Air Cleaner Housing (see Air Cleaner Housing Installation in the Fuel System (DFI) chapter) Fuel Tank (see Fuel Tank Installation in the Fuel System (DFI) chapter)
Output Voltage (without Plugs, Lean) Standard: DC 0.24 V or less
If the reading is out of the standard (with plugs: 0.8 V or more, without plugs: 0.24 V or less), 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 Connector [B] W/BL lead (ECU terminal 35) [C] BR/BK lead (ECU terminal 13) [D]
If the wiring is good, replace the sensor.
If the reading is within the standard (with plugs: 0.8 V or more, without plugs: 0.24 V or less), 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
Subthrottle Sensor Resistance Inspection
Exhaust Butterfly Valve Actuator Sensor (Service Code 34)DFI System Troubleshooting Guide
NOTE
This is not an exhaustive list, giving every possible cause for each
problem listed. It is meant
simply as a rough guide to assist the troubleshooting for some of the more
common difficulties in
DFI system.
The ECU may be involved in the DFI electrical and ignition system
tro ...
Wheel Rotation Sensor Rotor Inspection
Remove:
Wheels (see Front/Rear Wheel Removal in the
Wheels/Tires chapter)
Brake Disc Mounting Bolts [A]
Sensor Rotor [B]
Front Wheel [C]
Rear Wheel [D]
Visually inspect the wheel rotation sensor rotor.
If the rotor is deformed or damaged (chipped teeth [A]),
replace the ...
Swingarm Bearing, Sleeve Inspection
NOTICE
Do not remove the bearings for inspection. Removal
may damage them.
Inspect the needle bearings [A] and ball bearing installed
in the swingarm.
The rollers and ball in a bearing normally wear very little,
and wear is difficult to measure. Instead of measuring,
visually inspec ...