Yamaha YZ450FP 2023, Owner'S Service Manual

Page: 331 / 388

FUEL INJECTION SYSTEM
8-32
1 Connection of ignition coil cou-
pler.
Check the locking condition of
the coupler.
Disconnect the coupler, and
check the pins (for bent or bro-
ken terminals and locking condi-
tion of the pins).
Improperly connected

Con-
nect the coupler securely, or
repair/replace the wire harness.
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 7 and finish the service.
Condition is “Detected”

Go to
item 2.
2 Connection of wire harness
ECU coupler.
Check the locking condition of
the coupler.
Disconnect the coupler, and
check the pins (for bent or bro-
ken terminals and locking condi-
tion of the pins).
Improperly connected

Con-
nect the coupler securely, or
repair/replace the wire harness.
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 7 and finish the service.
Condition is “Detected”

Go to
item 3.
3 Wire harness continuity. Open or short circuit

Replace
the wire harness.
Between ignition coil coupler
and ECU coupler.
white–white
Between ignition coil coupler
and joint connector.
red–red
Between joint connector and
ECU coupler.
red–red
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 7 and finish the service.
Condition is “Detected”

Go to
item 4.
4 Mounted condition of ignition
coil.
Check for looseness or pinch-
ing.
Check the mounted condition
for correctness.
Improperly mounted sensor

Remount or replace the ignition
coil.
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 7 and finish the service.
Condition is “Detected”

Go to
item 5.
5 Defective ignition coil. (test the
primary coils for continuity)
Check the primary resistance of
the ignition coil.
Refer to “CHECKING THE
IGNITION COIL” on page 8-50.
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 7 and finish the service.
Condition is “Detected”

Go to
item 6.
6 Faulty ECU. Execute the diagnostic mode.
(Code No. 30)
No spark

Replace the ECU.
Service is finished.
Fault code No. 33
Item
Ignition coil: open or short circuit detected in the primary lead of
the ignition coil.