Yamaha YZ450FP 2023 Owner's Service Manual page 336

Fault code No. 46
Fault code No.
Item
Fail-safe system
Diagnostic code No.
Diagnostic tool display
Procedure
Probable cause of malfunc-
Item
tion and check
1 Connection of rectifier/regulator
coupler.
Check the locking condition of
the coupler.
Disconnect the coupler, and
check the pins (bent or broken
terminals and locking condition
of the pins).
2 Connection of AC magneto cou-
pler.
Check the locking condition of
the coupler.
Disconnect the coupler, and
check the pins (bent or broken
terminals and locking condition
of the pins).
3 Wire harness continuity.
4 Defective AC magneto.
5 Faulty ECU.
46
Vehicle system power supply: normal voltage is not supplied to the
ECU.
Able/Unable to start engine
Able/Unable to drive vehicle
—
—
—
Maintenance job
Improperly connected  Con-
nect the coupler securely, or
repair/replace the wire harness.
Improperly connected  Con-
nect the coupler securely, or
repair/replace the wire harness.
Open or short circuit  Replace
the wire harness.
Between rectifier/regulator cou-
pler and starter relay coupler.
red/white–red/white
Between starter relay coupler
and battery terminal.
red–red
Between rectifier/regulator cou-
pler and engine ground.
black–black
Between rectifier/regulator cou-
pler and AC magneto coupler.
white–white
Check the AC magneto.
Refer to "CHECKING THE STA-
TOR COIL" on page 8-52.
Replace the ECU.
8-37
FUEL INJECTION SYSTEM
Confirmation of service com-
pletion
Start the engine and let it idle for
approximately 5 seconds.
Check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is "Recovered"  Go
to item 6 and finish the service.
Condition is "Detected"  Go to
item 2.
Start the engine and let it idle for
approximately 5 seconds.
Check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is "Recovered"  Go
to item 6 and finish the service.
Condition is "Detected"  Go to
item 3.
Start the engine and let it idle for
approximately 5 seconds.
Check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is "Recovered"  Go
to item 6 and finish the service.
Condition is "Detected"  Go to
item 4.
Start the engine and let it idle for
approximately 5 seconds.
Check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is "Recovered"  Go
to item 6 and finish the service.
Condition is "Detected"  Go to
item 5.
Service is finished.