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 InspectionFront Wheel Rotation Sensor Signal Abnormal (Service Code b 42)
Measure the air gap between the front wheel rotation sensor
and sensor rotor.
Thickness Gauge [A]
Air Gap
Standard: 0.4 1.6 mm (0.02
0.06 in.)
If the measurement is not the standard, check each part
for deformation and looseness and correct accordingly.
If the measurement is t ...
Wheel Rotation Sensor Rotor Inspection
Remove:
Wheels (see Front/Rear Wheel Removal in the
Wheels/Tires chapter)
Brake Disc Mounting Bolts [A]
Sensor Rotor [B]
Front Wheel [C]
Rear Wheel [D]
Visually inspect the wheel rotation sensor rotor.
If the rotor is deformed or damaged (chipped teeth [A]),
replace the ...
Spark Plug Replacement
Remove the stick coils (see Stick Coil Removal in the
Electrical System chapter).
Remove the spark plugs using the 16 mm (0.63 in.) plug
wrench [A] vertically.
Replace the spark plug with new ones.
Standard Spark Plug
Type: NGK CR9EIA-9
Insert the spark plug vertically into the sp ...