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)Sidestand Switch Operation Inspection
Raise the rear wheel off the ground with the stand (see
Rear Wheel Removal in the Wheels/Tires chapter).
Inspect the sidestand switch [A] operation accordance to
below table.
Sidestand Switch Operation
If the sidestand switch operation does not work, inspect
or replace the foll ...
Air Suction System Damage Inspection
Separate the air switching valve hose [A] from the lower
air cleaner housing [B] (see Air Cleaner Housing Removal
in the Fuel System (DFI) chapter).
Connect the following parts temporarily.
Fuel Pump Lead Connector [A]
Extension Tube [B]
Air Cleaner Housing (see Air Cleaner Hou ...
Chain Slack Inspection
Set the motorcycle up on its side
stand.
Rotate the rear wheel to find the position
where the chain is tightest, and
measure the maximum chain slack
by pulling up and pushing down the
chain midway between the engine
sprocket and rear wheel sprocket.
A. Chain Slack
If the ...