Yamaha YZ450F Owner's Service Manual page 205

Fault code No.
Symptom
Fail-safe system
Diagnostic code No.
FI diagnostic tool display
Checking method
Item Item/components and probable cause
1 Installed condition of sensor.
• Make sure that the installation position is cor-
rect.
• Make sure that there are no problems with the
installation.
2 Defective throttle position sensor.
3 Malfunction in ECU.
16
Signal from throttle position sensor does not change.
Able to start
Able to drive
D01
• 15–19° (Fully closed position)
• 95–101° (Fully opened position)
• Check with throttle valves fully closed.
• Check with throttle valves fully open.
FUEL INJECTION SYSTEM
Check or maintenance job
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.
Incorrect installation position →
Properly install.
Execute the diagnostic mode (di-
agnostic code No. D01).
When throttle is fully closed: A
value of 15–19 is indicated.
When throttle is fully opened: A
value of 95–101 is indicated.
Displayed value is out of specifica-
tion → Replace.
Replace the ECU.
7-19
Checking method
Set the switch on the FI di-
agnostic tool sub-wire har-
ness to "ON", and then
operate the throttle.
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 dis-
played → Refer to item 2.
Set the switch on the FI di-
agnostic tool sub-wire har-
ness to "ON", and then
operate the throttle.
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 dis-
played → Refer to item 3.