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)Charging Condition Inspection
Battery charging condition can be checked by measuring
battery terminal voltage with a digital voltmeter [A].
Remove the seat (see Seat Removal in the Frame chapter).
Disconnect the battery terminals.
NOTICE
Be sure to disconnect the negative (–) cable first.
Measure the battery ...
Brake Disc Wear Inspection
Measure the thickness of each disc [A] at the point where
it has worn the most.
If the disc has worn past the service limit, replace it.
Measuring Area [B]
Brake Disc Thickness Standard:
Front 5.3 5.7 mm (0.21
0.22 in.)
Rear 4.8 5.2 mm (0.19
0.20 in.)
Service Limit:
Front 5. ...
Fuel Injector Output Voltage Inspection
NOTE
Be sure the battery is fully charged.
Turn the ignition switch to OFF.
Remove the ECU (see ECU Removal).
Do not disconnect the ECU connector
Connect a digital meter [A] to the connector (gray) [B] with
the needle adapter set.
Special Tool - Needle Adapter Set: 57001-1457
...