Yamaha YZ450F(D) Owner's Service Manual page 198

Fault code No.
Symptom
Fail-safe system
Diagnostic code No.
FI diagnostic tool display
Checking method
Item Item/components and probable cause
5 Defective crankshaft position sensor.
6 Malfunction in ECU.
If fault code Nos. 13 and 14 are both displayed, perform the checks and maintenance jobs for fault code No. 13 first.
Fault code No.
Symptom
Fail-safe system
Diagnostic code No.
FI diagnostic tool display
Checking method
Item Item/components and probable cause
1 Check the connection and locking condition of
the intake air pressure sensor coupler.
Disconnect the coupler and check the pins.
(bent or broken terminals and locking condition
of the pins)
2 Check the connection and locking condition of
the wire harness ECU coupler.
Disconnect the coupler and check the pins.
(bent or broken terminals and locking condition
of the pins)
12
No normal signals are received from the crankshaft position sensor.
Able to start
Able to drive
—
—
—
13
Intake air pressure sensor signal is not received properly.
Able to start
Able to drive
D03
Intake air pressure
Crank the engine. (If the display value changes, the performance is OK.)
FUEL INJECTION SYSTEM
Check or maintenance job
Sensor malfunction → Replace.
Refer to "CHECKING THE AC
MAGNETO" section.
Replace the ECU.
Check or maintenance job
Poor connection → Properly con-
nect, repair, or replace.
Poor connection → Properly con-
nect, repair, or replace.
7-14
Checking method
Crank the engine and
check the fault code dis-
play.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item
6.
Checking method
Set the switch on the FI di-
agnostic tool sub-wire har-
ness to "ON", and then
check the fault code dis-
play.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item 2.
Set the switch on the FI di-
agnostic tool sub-wire har-
ness to "ON", and then
check the fault code dis-
play.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item 3.