Yamaha YZ450F Owner's Service Manual page 213

Fault code No.
Symptom
Fail-safe system
Diagnostic code No.
FI diagnostic tool display
Checking method
Item Item/components and probable cause
4 Installed condition of ignition coil
5 Defective ignition coil. (test the primary coils for
continuity)
6 Malfunction in ECU.
33
Ignition system circuit signal is not received properly.
Unable to start
Unable to drive
D30
Actuates the ignition coil for five times every second.
The "WARNING" LED on the FI diagnostic tool comes on each time the ignition coil is ac-
tuated.
Check the spark five times.
• Connect an ignition checker.
FUEL INJECTION SYSTEM
Check or maintenance job
Check that the sensor is installed
securely and that there are no
pinched leads.Check that the ECU
is installed securely and that there
are no pinched leads.
Incorrect installation → Reinstall
or repair.
Defective → Replace.
Refer to "CHECKING THE IGNI-
TION COIL".
Execute the diagnostic mode (di-
agnostic code No. D30).
No spark → Replace the ECU.
7-27
Checking method
Start the engine and let it
idle for approximately 5
seconds.
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 dis-
played → Refer to item 5.
Start the engine and let it
idle for approximately 5
seconds.
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 dis-
played → Refer to item 6.