Yamaha YZ450FA Automobile User Manual


 
7-35
FUEL INJECTION SYSTEM
3 Check the connection and locking con-
dition of the wire harness 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 and
let it idle for approxi-
mately 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 displayed Re-
fer to item 4.
4 Continuity of harness Open or short circuit Re-
place.
Between injector coupler
and ECU coupler.
(Red–Red)
(Red/Black–Red/Black)
Start the engine and
let it idle for approxi-
mately 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 displayed Re-
fer to item 5.
5 Malfunction in ECU. Replace the ECU.
Fault code No. 39
Symptom Injection system circuit signal is not received properly.
Fail-safe system Unable to start
Unable to drive
Diagnostic code No. D36
FI diagnostic tool dis-
play
Actuates the injector for five times every second.
The "WARNING" LED on the FI diagnostic tool comes on each time the
fuel injector is actuated.
Checking method Check the operating sound of the injector five times.
Item Item/components and probable cause Check or maintenance job Checking method