Yamaha YZF-R1S Service Manual - page 373
7-29
FUEL INJECTION SYSTEM
FI
Speed sensor output voltage
When sensor is on
DC 4.8 V or more
When sensor is off
DC 0.6 V or less
Tester positive probe
! white
Tester negative probe
! black/blue
1
2
Fault code No.
42
Symptom
1 No normal signals are received from the speed sensor.
2 Open or short circuit is detected in the neutral switch.
Used diagnostic code
No. 07 (speed sensor)
! A1 X A4
No. 21 (neutral switch)
! B1 X B4
Order
Inspection operation item and probable
cause
Operation item and countermeasure
Reinstatement
method
A1
Connected condition of speed sensor
connector
Inspect the coupler for any pins that
may have pulled out.
Check the locking condition of the
coupler.
If there is a malfunction, repair it and connect it
securely.
Speed sensor coupler
Main wiring harness ECU coupler
Reinstated by
starting the
engine, and
inputting the
vehicle speed
signals by
ti
th
A2
Open or short circuit in speed sensor
lead.
Repair or replace if there is an open or short circuit.
Between sensor coupler and ECU coupler.
Blue – Blue
White / Yellow – White / Yellow
Black / Blue – Black / Blue
operating the
motorcycle at a
low speed of
20 to 30 km / h.
A3
Defective speed sensor
Execute the diagnostic mode (Code No.07).
Replace if defective.
1. Measure the speed sensor output voltage.
2. Connect the pocket tester (DC 20 V) to the
speed sensor coupler terminal as shown.
3. Measure the speed sensor output voltage.
4. Is the speed sensor OK?
A4
Gear for detecting vehicle speed has
broken.
Replace if defective.
Refer to “TRANSMISSION” in chapter 5.
Order
Inspection operation item and probable
cause
Operation item and countermeasure
Reinstatement
method.
B1
Connected condition of connector
Inspect the coupler for any pins that
may have pulled out.
Check the locking condition of the
coupler.
If there is a malfunction, repair it and connect it
securely.
Neutral switch connector
Main wiring harness ECU coupler
Reinstated by
starting the
engine, and
inputting the
vehicle speed
i
l b
B2
Open or short circuit in neutral switch
lead.
Repair or replace if there is an open or short circuit.
Between switch connector and ECU coupler
Sky blue – Black / Yellow
signals by
operating the
motorcycle at a
low speed of
B3
Defective neutral switch
Execute the diagnostic mode (Code No.21).
Replace if defective.
Refer to “CHECKING THE SWITCHES” in
chapter 8.
low s eed of
20 to 30 km / h.
B4
Faulty shift drum
(neutral detection area)
Replace if defective.
Refer to “TRANSMISSION” in chapter 5.