Yamaha YZ250F(E) Owner's Service Manual page 305

Fault code
Symptom
Fail-safe system
Diagnostic code No.
Diagnostic tool display
Procedure
Or- Probable cause of malfunc-
der tion and check
1 Mounted condition of throttle
position sensor.
Check for looseness or
pinching.
Check the mounted condition
for correctness.
2 Defective throttle position
sensor.
3 Faulty ECU
16
Throttle position sensor: stuck throttle position sensor is de-
tected.
Able to start engine
Able to drive vehicle
01
Displays the throttle angle.
• 11–14 (throttle in fully closed position)
• 109–116 (throttle in fully opened position)
Check with throttle valves fully closed.
Check with throttle valves fully opened.
Maintenance job
Improperly mounted sensor
 Remount or replace the
sensor.
Refer to "ADJUSTING THE
THROTTLE POSITION SEN-
SOR" on page 7-9.
Execute the diagnostic mode.
(Code No. d:01)
When the throttle is fully
closed, 11–14 displays.
When the throttle is fully
opened, 109–116 displays.
Incorrect display range 
Replace the throttle position
sensor.
Replace the ECU.
8-19
FUEL INJECTION SYSTEM
Reinstatement method
Turn "ON" the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
Turn "ON" the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.