Yamaha MT-01 T 2005 Service Manual page 374

Fault code No. 42
Diagnostic code No.
Order Item/components and probable
cause
B-1 Connections
• Neutral switch coupler
• Main wire harness ECU coupler
B-2 Open circuit in neutral switch lead.
B-3 Faulty shift drum (neutral detection
area).
B-4 Defective neutral switch.
Symptom A. No normal signals are received from the speed sensor.
B. Open circuit is detected in the neutral switch.
A 07 Speed sensor
B 21 Neutral switch
FUEL INJECTION SYSTEM
Check or maintenance job
• Check the coupler for any pins
that may be pulled out.
• Check the locking condition of
the coupler.
• If there is a malfunction, repair it
and connect the coupler
securely.
• Repair or replace if there is an
open circuit.
• Between neutral switch coupler
and fuel pump relay coupler.
(sky blue–sky blue)
• Between fuel pump relay
coupler and ECU coupler.
(blue/yellow–blue/yellow)
• Replace if defective.
Refer to "TRANSMISSION" on
page 5-92.
• Execute the diagnostic mode.
(Code No.21)
• Replace if defective.
Refer to "CHECKING THE
SWITCHES" on page 7-89.
7-59
Reinstatement
method
Starting the
engine, and
activating the
vehicle speed
sensor by
operating the
vehicle at 20 to
30 km/h.