Yamaha YZ450FA 2011 Owner's Service Manual page 301

Fault code No.
Symptom
Fail-safe system
Diagnostic code No.
FI diagnostic tool dis-
play
Checking method
Item Item/components and probable cause Check or maintenance job
3 Malfunction of the rectifier/regulator.
4 Defective AC magneto.
5 Malfunction in ECU.
46
Power supply to the ECU is not normal.
Able to start (depending on circumstances)
Able to drive vehicle (depending on circumstances)
—
—
—
Defective → Replace.
Refer to "CHECKING THE
RECTIFIER/REGULATOR"
section.
Defective → Replace.
Refer to "CHECKING THE
AC MAGNETO" section.
Replace the ECU.
7-39
FUEL INJECTION SYSTEM
Checking method
Start the engine, set
the switch on the FI di-
agnostic tool sub-wire
harness to "OFF"
while the engine is
idling, and let the en-
gine continue to idle
for 5 seconds or more.
After completing the
above operation,
check whether a fault
code number is dis-
played.
Fault code number
is not displayed →
Service is finished.
Fault code number
is displayed → Re-
fer to item 4.
Start the engine, set
the switch on the FI di-
agnostic tool sub-wire
harness to "OFF"
while the engine is
idling, and let the en-
gine continue to idle
for 5 seconds or more.
After completing the
above operation,
check whether a fault
code number is dis-
played.
Fault code number
is not displayed →
Service is finished.
Fault code number
is displayed → Re-
fer to item 5.