Yamaha YZF-R125 Service Manual page 321

YamahaR125.COM
Fault code No. 42
Diagnostic code No.
Order Item/components and probable
cause
1 Connections
• Speed sensor coupler
• Wire harness ECU coupler
2 Open or short circuit in wire harness
and/or sub-wire harness.
3 Defective speed sensor.
Fault code No. 44
Diagnostic code No.
Order Item/components and probable
cause
1 Malfunction in ECU.
Symptom No normal signals are received from the speed sensor.
07 Speed sensor
Symptom Error is detected while reading from or writing on EE-
PROM.
60 EEPROM fault code display
FUEL INJECTION SYSTEM
Check or maintenance job
• Check 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 the coupler se-
curely.
• Repair or replace if there is an
open or short circuit.
• Between speed sensor coupler
and ECU coupler.
(gray–gray)
(gray/black–gray/black)
(gray/red–gray/red)
• Execute the diagnostic mode.
(Code No.07)
• Replace if defective.
Refer to "CHECKING THE
SPEED SENSOR" on page
8-72.
Check or maintenance job
• Execute the diagnostic mode.
(Code No.60).
• 01 is displayed.
Readjust CO.
Refer to "ADJUSTING THE EX-
HAUST GAS VOLUME" on
page 3-5.
Replace ECU if defective.
NOTE:
Do not perform replacing ECU
with the main switch set to "ON".
8-50
Reinstatement
method
Start the en-
gine, and input
the vehicle
speed signals
by operating
the vehicle at
20 to 30 km/h.
Reinstatement
method
Setting the
main switch to
"ON".