Yamaha YZF-R1S Service Manual page 373

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