NOTE
Be sure the battery is fully charged.
Main Harness [B] Vehicle-down Sensor [C]
Special Tool - Measuring Adapter: 57001-1700

Vehicle-down Sensor Input Voltage Connections to Adapter: Digital Meter (+) → R (sensor BL) lead Digital Meter (–) → BK (sensor BR/BK) lead

Input Voltage
Standard: DC 4.75
5.25 V
If the reading is within the standard, check the output voltage (see Vehicle-down Sensor Output Voltage Inspection).
If the reading is out of the standard, remove the ECU and check the wiring for continuity between main harness connectors.
Special Tool - Hand Tester: 57001-1394
Disconnect the ECU and sensor connectors.
Wiring Continuity Inspection ECU Connector [A] ←→ Vehicle-down Sensor Connector [B] BL lead (ECU terminal 9) [C] BR/BK lead (ECU terminal 13) [D]

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).
Vehicle-down Sensor Installation
Vehicle-down Sensor Output Voltage InspectionCylinder Head Cover Removal
Remove:
Air Suction Valves (see Air Suction Valve Removal)
Throttle Body Assy (see Throttle Body Assy Removal in
the Fuel System (DFI) chapter)
Stick Coils (see Stick Coil Removal in the Electrical System
chapter)
Remove the clamps [A].
Turn up the front side of the heat insulation ...
Turn Signal Switch
When the turn signal switch is
pushed to the left ( ) or right
( ), the corresponding turn signals
blink on and off.
To stop blinking, push the switch in.
Horn Button
When the horn button is pushed, the
horn sounds
LAP/Passing Button
When the LAP/passing button is
pushed, the headlight hi ...
Inquiries to Rider
Each rider reacts to problems in different ways, so it is important to
confirm what kind of condition
the rider is dissatisfied with.
Try to find out exactly what problem occurs under exactly what
conditions by asking the rider; knowing
this information may help you reproduce the prob ...