Yamaha YZ250FX 2021, Owner'S Service Manual

Page: 320 / 378

FUEL INJECTION SYSTEM
8-33
Fault code No. 33
3 Faulty ECU. Execute the diagnostic mode.
(Code No. 08)
When the vehicle is upright:
0.4–1.4 (V)
When the vehicle is overturned:
3.7–4.4 (V)
Improper display

Replace the
ECU.
Service is finished.
4 Delete the fault code. Confirm that the fault code has
a condition of “Recovered”
using the Yamaha diagnostic
tool, and then delete the fault
code.
Fault code No. 33
Item
Ignition coil: open or short circuit detected in the primary lead of
the ignition coil.
Fail-safe system
Unable to start engine
Unable to drive vehicle
Diagnostic code No.
30
Actuation
Actuates the ignition coil five times at one-second intervals.
“WARNING” on the Yamaha diagnostic tool blinks five times when the
ignition coil is actuated.
Procedure
Check that a spark is generated five times.
•
Connect an ignition checker.
Item
Probable cause of malfunc-
tion and check
Maintenance job
Confirmation of service com-
pletion
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 8 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 8 and finish the service.
Condition is “Detected”

Go to
item 3.
Fault code No. 30
Item The vehicle has overturned.