Yamaha YZ450FF 1SL-28199-11, Owner'S Service Manual

Page: 314 / 358

FUEL INJECTION SYSTEM
8-24
TIP
Disconnect the fuel pump coupler when this diagnostic tool is used.
6 Faulty ECU Execute the diagnostic mode.
(Code No. 30)
No spark

Replace the
ECU.
Fault code 39
Symptom Injector: open or short circuit detected.
Fail-safe system Unable to start engine
Unable to drive vehicle
Diagnostic code No. 36
Actuation Actuates injector five times at one-second intervals.
“WARNING” on the Yamaha diagnostic tool blinks five times when
the injector is actuated.
Procedure Check that injector is actuated five times by listening for the oper-
ating sound.
Or-
der
Probable cause of malfunc-
tion and check
Maintenance job Reinstatement method
1 Connection of injector cou-
pler.
Check the locking condition
of the coupler.
Disconnect the coupler, and
check the pins (for bent or
broken terminals and locking
condition of the pins).
Improperly connected

Connect the coupler secure-
ly, or repair/replace the wire
harness.
After starting the engine, idle
this and wait about 5 sec-
onds.
Fault code No. is not dis-
played

Repair is finished.
Fault code No. is displayed

Go to next order.
2 Defective injector. Check the injector.
“CHECKING THE FUEL IN-
JECTOR” on page 8-46.
After starting the engine, idle
this and wait about 5 sec-
onds.
Fault code No. is not dis-
played

Repair is finished.
Fault code No. is displayed

Go to next order.
3 Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler, and
check the pins (for bent or
broken terminals and locking
condition of the pins).
Improperly connected

Connect the coupler secure-
ly, or repair/replace the wire
harness.
After starting the engine, idle
this and wait about 5 sec-
onds.
Fault code No. is not dis-
played

Repair is finished.
Fault code No. is displayed

Go to next order.
Fault code 33
Symptom
Ignition coil: open or short circuit detected in the primary lead
of the ignition coil.