Yamaha YZF-R125, Service Manual

Page: 320 / 356

FUEL INJECTION SYSTEM
8-49
Fault code No. 39 Symptom Fuel injector: open or short circuit detected.
Diagnostic code No. 36 Fuel injector
Order Item/components and probable
cause
Check or maintenance job Reinstatement
method
1 Connections
• Fuel injector coupler
• Main wire harness ECU coupler • Check the couplers for any pins
that may have pulled out.
• Check the locking condition of
the couplers.
• If there is a malfunction, repair it
and connect the coupler se-
curely.
Cranking the
engine.
2 Open or short circuit in wire harness. • Repair or replace if there is an
open or short circuit.
• Between fuel injector coupler
and ECU coupler.
(red/white–red/white)
(orange/black–orange/black)
3 Defective fuel injector. • Execute the diagnostic mode.
(Code No.36)
• Replace if defective.
Refer to “CHECKING THE
FUEL INJECTOR” on page 7-6.
Fault code No. 41 Symptom Lean angle sensor: open or short circuit detected.
Diagnostic code No. 08 Lean angle sensor
Order Item/components and probable
cause
Check or maintenance job Reinstatement
method
1 Connections
• Lean angle sensor coupler
• Main wire harness ECU coupler • 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.
Setting the
main switch to
“ON”.
2 Open or short circuit in wire harness. • Repair or replace if there is an
open or short circuit.
• Between lean angle sensor
coupler and ECU coupler.
(gray/red–gray/red)
(yellow/green–yellow/green)
(gray/black–gray/black)
3 Defective lean angle sensor. • Execute the diagnostic mode.
(Code No.08)
• Replace if defective.
Refer to “CHECKING THE
LEAN ANGLE SENSOR” on
page 8-69.
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