Yamaha YZ450FA Automobile User Manual


 
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FUEL INJECTION SYSTEM
Fault code No. 46
Symptom Power supply to the ECU is not normal.
Fail-safe system Able to start (depending on circumstances)
Able to drive vehicle (depending on circumstances)
Diagnostic code No.
FI diagnostic tool dis-
play
Checking method
Item Item/components and probable cause Check or maintenance job Checking method
1 Check the connection and locking con-
dition of the ECU coupler.
Disconnect the coupler and check the
pins. (bent or broken terminals and
locking condition of the pins)
Poor connection Properly
connect, repair, or replace.
Start the engine, set
the switch on the FI di-
agnostic tool sub-wire
harness to "OFF"
while the engine is
idling, and let the en-
gine continue to idle
for 5 seconds or more.
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 displayed Re-
fer to item 2.
2 Continuity of harness Open or short circuit Re-
place.
Between Rectifier/regulator
and the ECU
(Red–Red/White)
Between Rectifier/regulator
and the condenser.
(Red–Red)
Start the engine, set
the switch on the FI di-
agnostic tool sub-wire
harness to "OFF"
while the engine is
idling, and let the en-
gine continue to idle
for 5 seconds or more.
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 displayed Re-
fer to item 3.