If this service code appears, check that the following parts are correctly.
Crankshaft Sensor Gear Position Switch Starter Lockout Switch Main Throttle Sensor Rear Wheel Rotation Sensor
If these parts are normal, check the ESD ECU for its ground and power supply (see ESD ECU Power Supply Inspection).
ESD ECU Removal
ESD ECU Installation
Refer to the ESD (Electronic Steering Damper) ECU Installation in the Steering chapter.
ESD ECU Power Supply Inspection

If the connector is clogged with mud or dust, blow it off with compressed air.
If the terminals of the main harness connector are damaged, replace the main harness.
If the terminals of the ESD ECU connectors are damaged, replace the ESD ECU.
Special Tool - Hand Tester: 57001-1394

ESD ECU Grounding Inspection Connections: (I) BK/Y lead (ESD ECU terminal 9) ←→ Battery (–) Terminal (II) Engine Ground ←→ Battery (–) Terminal Criteria: Both: 0 Ω
If no continuity, check the connector, the engine ground lead, or main harness, and repair or replace them if necessary.
If the wiring is good, check the power source voltage of the ESD ECU.
NOTE
Be sure the battery is fully charged.

Special Tool - Needle Adapter Set: 57001-1457
ESD ECU Power Supply Inspection Connections:
(I) Digital Meter (+) → Terminal 18 (BR/BK) Digital Meter (–) → Battery (–) terminal
Ignition Switch OFF: 0 V
Ignition Switch ON: Battery Voltage
If the reading is out of the specification, check the following.
Main Fuse 30 A (see Fuse Inspection in the Electrical System chapter) Electronic Steering Damper Fuse 10 A (see Fuse Inspection in the Electrical System chapter) Power Source Wiring (see wiring diagram in this section)
If the fuse and wiring are good, replace the ESD ECU (see ESD (Electronic Steering Damper) ECU Removal/Installation in the Steering chapter).
ESD ECU Power Source Circuit

1. Ignition Switch
2. ESD ECU
3. Engine Ground
4. Battery
5. Starter Relay
6. Main Fuse 30 A
7. Frame Ground 3
8. Fuse Box 1
9. ESD Fuse 10 A
ESD Actuator Input Voltage InspectionRear Wheel Rotation Sensor Removal
NOTICE
The wheel rotation sensor should be handled carefully,
never struck sharply, as with a hammer, or allowed
to fall on a hard surface since the wheel rotation
sensor is precision made. Be careful not to get
water or mud on the wheel rotation sensor.
Do not try to disassemble or repair t ...
Oil Pump Drive Gear Shaft Installation
Apply molybdenum disulfide grease [A] to the oil pump
drive gear shaft.
Apply molybdenum disulfide oil solution to the followings.
Transmission Case [B]
Crankcase [C]
Install the oil pump drive gear shaft and washer [D] as
shown in the figure.
Install the new circlip [E] into the ...
Throttle Grip and Cables
Free Play Inspection
Refer to the Throttle Control System Inspection in the Periodic
Maintenance chapter.
Free Play Adjustment
Refer to the Throttle Control System Inspection in the Periodic
Maintenance chapter.
Cable Installation
Install the throttle cables in accordance with the Cable,
...