NOTE
Be sure the battery is fully charged.

Main Harness [B] Subthrottle Valve Actuator [C]
Special Tool - Measuring Adapter: 57001-1700
Connect the peak voltage adapter [D] and a digital meter [E] to the measuring adapter leads.
Special Tool - Peak Voltage Adapter: 57001-1415 Type: KEK-54-9-B

Special Tool - Peak Voltage Adapter: 57001-1415 Type: KEK-54-9-B
Subthrottle Valve Actuator Input Voltage Connections to Adapter:
(I) Digital Meter (+) → R (actuator BK/O) lead Digital Meter (–) → Battery (–) terminal (II) Digital Meter (+) → BK (actuator G) lead Digital Meter (–) → Battery (–) terminal (III) Digital Meter (+) → W (actuator P/BL) lead Digital Meter (–) → Battery (–) terminal (IV) Digital Meter (+) → Y (actuator Y/BK) lead Digital Meter (–) → Battery (–) terminal
Input Voltage
Standard: About DC 8.5
10.5 V and
then 0 V or
About DC 8.5
10.5 V
If the reading is in specification, but the actuator does not operate, replace the throttle body assy.
If the reading is out of the specification, remove the ECU and check the wiring for continuity between main harness connector.
Special Tool - Hand Tester: 57001-1394
Disconnect the ECU and actuator connectors.

Wiring Continuity Inspection ECU Connector [A] ←→ Subthrottle Valve Actuator Connector [B] G lead (ECU terminal 15) [C] BK/O lead (ECU terminal 2) [D] P/BL lead (ECU terminal 14) [E] Y/BK lead (ECU terminal 1) [F]
If the wiring is good, 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).
Subthrottle Valve Actuator Circuit

1. ECU
2. Subthrottle Valve Actuator
Subthrottle Valve Actuator Resistance InspectionIC Igniter Inspection
The IC igniter is built in the ECU [A].
Refer to the following items.
Interlock Operation Inspection (see Interlock Operation
Inspection)
Ignition System Troubleshooting (see Ignition System
section)
ECU Power Supply Inspection (see ECU Power Supply
Inspection in the Fuel System (D ...
Coolant Level Inspection
Situate the motorcycle so that it is
perpendicular to the ground.
Check the coolant level through the
coolant level gauge on the reserve
tank located to the left of the engine.
The coolant level should be between
the “F” (Full) and “L” (Low) level lines.
A. Reserve Ta ...
Piston Ring, Piston Ring Groove Wear Inspection
Check for uneven groove wear by inspecting the ring seating.
The rings should fit perfectly parallel to groove surfaces.
If not, replace the piston and all the piston rings.
With the piston rings in their grooves, make several measurements
with a thickness gauge [A] to determine pisto ...