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 InspectionCrankshaft Installation
NOTE
If the crankshaft is replaced with a new one, refer to
the Connecting Rod Big End Bearing/Crankshaft Main
Bearing Insert Selection in the Specifications.
NOTICE
If the crankshaft, bearing inserts, or crankcase
halves are replaced with new ones, select the bearing
inserts and check cleara ...
Air Cleaner Element Replacement
NOTE
In dusty areas, the element should be replaced more
frequently than the recommended interval.
WARNINGIf dirt or dust is allowed to pass through
into the
throttle body assy, the throttle may become stuck,
possibly causing accident. Replace the air cleaner
element according ...
Starter Clutch Installation
Replace the O-ring [A] with a new one and apply grease.
Apply molybdenum disulfide grease to the starter clutch
shaft [B].
Install:
Starter Clutch [C]
Spacer (Small Diameter) [D]
Spacer (Large Diameter) [E]
Starter Clutch Shaft
Starter Clutch Shaft Holder [F]
Turn the O-ring si ...