Yamaha YZ450F Owner's Service Manual page 199

TROUBLESHOOTING DETAILS
This section describes the countermeasures per fault code number displayed on the FI diagnostic tool. Check and service
the items or components that are the probable cause of the malfunction following the order given. After the check and ser-
vice of the malfunctioning part have been completed, reset the FI diagnostic tool display according to the "Reinstatement
method".
Fault code No.
Fault code number displayed on the FI diagnostic tool when the engine failed to work normally. Refer to "FAULT CODE
TABLE".
Diagnostic code No.
Diagnostic code number to be used when the diagnostic mode is operated. Refer to "DIAGNOSTIC CODE TABLE".
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 crankshaft position 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)
3 Continuity of harness
4 Installed condition of sensor.
Check that the gap between the crankshaft po-
sition sensor and the rotor is 0.85 mm.
12
No normal signals are received from the crankshaft position sensor.
Able to start
Able to drive
—
—
—
FUEL INJECTION SYSTEM
Check or maintenance job
Poor connection → Properly con-
nect, repair, or replace.
Poor connection → Properly con-
nect, repair, or replace.
Open or short circuit → Replace.
Between the crankshaft position
sensor coupler and ECU coupler.
(Gray–Gray)
(Black/Blue–Black/Blue)
Check that the sensor is installed
securely and that there are no
pinched leads.Check that the ECU
is installed securely and that there
are no pinched leads.
Incorrect installation → Reinstall
or repair.
7-13
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
2.
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 3.
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 4.
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
5.