2017 YAMAHA WR 250F air condition

FUEL INJECTION SYSTEM
9-36
2 Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected 
Connect the coupler securely
or repair/replace the wire har-
ness.Crank the engine.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 3.
3 Wire harness continuity. Open or short circuit  Re-
place the wire harness.
Between the crankshaft posi-
tion sensor coupler and ECU
coupler.
black/blue–black/blue
gray–grayCrank the engine.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 4.
4 Installed condition of crank-
shaft position sensor.
Check for looseness or
pinching.
Check the gap between the
crankshaft position sensor
and the pickup rotor.Improperly installed sensor
 Reinstall or replace the
sensor.
Refer to “GENERATOR AND
STARTER CLUTCH” on
page 6-66.Crank the engine.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 5.
5 Defective crankshaft position
sensor.Check the crankshaft position
sensor.
Refer to “CHECKING THE
CRANKSHAFT POSITION
SENSOR” on page 9-75.Crank the engine.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 6.
6 Malfunction in ECU. Replace the ECU. Fault code No. 12
ItemCrankshaft position sensor: no normal signals are received
from the crankshaft position sensor.

FUEL INJECTION SYSTEM
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TIP
• If fault code numbers 13 and 14 are both displayed, perform the checks and maintenance jobs for
fault code number 13 first.
• Before troubleshooting, disconnect the starter motor lead from the starter relay.
Fault code No. 13
Item Intake air pressure sensor: open or short circuit detected.
Fail-safe systemAble to start engine
Able to drive vehicle
Diagnostic code No.03
Diagnostic tool displayDisplays the intake air pressure.
ProcedureOperate the throttle while pushing the start switch.(If the display
value changes, the performance is OK.)
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation of service
completion
1 Connection of intake air pres-
sure sensor coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected 
Connect the coupler securely
or repair/replace the wire har-
ness.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 2.
2 Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected 
Connect the coupler securely
or repair/replace the wire har-
ness.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 3.
3 Wire harness continuity. Open or short circuit  Re-
place the wire harness.
Between intake air pressure
sensor coupler and ECU cou-
pler.
black/blue–black/blue
pink–pink
blue–bluePush the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 4.
4 Installed condition of intake
air pressure sensor.
Check for looseness or
pinching.Improperly installed sensor
 Reinstall or replace the
sensor.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 5.

FUEL INJECTION SYSTEM
9-38
TIP
• If fault code numbers 13 and 14 are both displayed, perform the checks and maintenance jobs for
fault code number 13 first.
• Before troubleshooting, disconnect the starter motor lead from the starter relay. 5 Defective intake air pressure
sensor.Execute the diagnostic mode.
(Code No. 03)
When engine is stopped:
Atmospheric pressure at the
current altitude and weather
conditions is indicated.
At sea level: Approx. 101 kPa
1000 m above sea level: Ap-
prox. 90 kPa
2000 m above sea level: Ap-
prox. 80 kPa
3000 m above sea level: Ap-
prox. 70 kPa
When engine is cranking:
Make sure that the indication
value changes.
The value does not change
when engine is cranking. 
Check the intake air pressure
sensor.
Replace if defective.
Refer to “CHECKING THE
INTAKE AIR PRESSURE
SENSOR” on page 9-80.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 6.
6 Malfunction in ECU. Replace the ECU.
Fault code No. 14
ItemIntake air pressure sensor: hose system malfunction (clogged
or detached hose).
Fail-safe systemAble to start engine
Able to drive vehicle
Diagnostic code No.03
Diagnostic tool displayDisplays the intake air pressure.
ProcedureOperate the throttle while pushing the start switch.(If the display
value changes, the performance is OK.)
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation of service
completion
1 The intake air pressure sen-
sor hose is damaged, discon-
nected, clogged, twisted or
bent.Repair or replace the sensor
hose.Start the engine and let it idle
for approximately 5 seconds.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 2. Fault code No. 13
Item Intake air pressure sensor: open or short circuit detected.

FUEL INJECTION SYSTEM
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TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay. 2 Defective intake air pressure
sensor.Execute the diagnostic mode.
(Code No. 03)
When engine is stopped:
Atmospheric pressure at the
current altitude and weather
conditions is indicated.
At sea level: Approx. 101 kPa
1000 m above sea level: Ap-
prox. 90 kPa
2000 m above sea level: Ap-
prox. 80 kPa
3000 m above sea level: Ap-
prox. 70 kPa
When engine is cranking:
Make sure that the indication
value changes.
The value does not change
when engine is cranking. 
Check the intake air pressure
sensor.
Replace if defective.
Refer to “CHECKING THE
INTAKE AIR PRESSURE
SENSOR” on page 9-80.
Fault code No. 15
Item Throttle position sensor: open or short circuit detected.
Fail-safe systemAble to start engine
Able to drive vehicle
Diagnostic code No.01
Diagnostic tool displayThrottle position sensor signal
• 11–14 (fully closed position)
• 109–116 (fully open position)
Procedure• Check with throttle valve fully closed.
• Check with throttle valve fully open.
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation of service
completion
1 Connection of throttle posi-
tion sensor coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected 
Connect the coupler securely
or repair/replace the wire har-
ness.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 2. Fault code No. 14
ItemIntake air pressure sensor: hose system malfunction (clogged
or detached hose).

FUEL INJECTION SYSTEM
9-40
2 Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected 
Connect the coupler securely
or repair/replace the wire har-
ness.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 3.
3 Wire harness continuity. Open or short circuit  Re-
place the wire harness.
Between throttle position
sensor coupler and ECU cou-
pler.
black/blue–black/blue
yellow–yellow
blue–bluePush the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 4.
4 Installed condition of throttle
position sensor.
Check for looseness or
pinching.Improperly installed sensor
 Reinstall or replace the
sensor.
Refer to “ADJUSTING THE
THROTTLE POSITION SEN-
SOR” on page 8-11.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 5.
5 Applied voltage of throttle po-
sition sensor lead.Check the applied voltage.
(black/blue–blue)
Refer to “CHECKING THE
THROTTLE POSITION SEN-
SOR” on page 9-79.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 6.
Location of discon-
nected leadOutput
voltage
Disconnected
ground lead5 V
Disconnected out-
put lead0 V
Disconnected
power supply lead0 V
6 Defective throttle position
sensor.Check throttle position sen-
sor signal.
Execute the diagnostic mode.
(Code No. 01)
When the throttle valve is fully
closed:
A value of 11–14 is indicated.
When throttle valve is fully
open:
A value of 109–116 is indicat-
ed.
An indicated value is out of
the specified range.  Re-
place the throttle position
sensor.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 7. Fault code No. 15
Item Throttle position sensor: open or short circuit detected.

FUEL INJECTION SYSTEM
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TIP
• Make sure that the engine is completely cool before checking the coolant temperature sensor.
• Before troubleshooting, disconnect the starter motor lead from the starter relay.
Fault code No. 21
Item Coolant temperature sensor: open or short circuit detected.
Fail-safe systemAble to start engine
Able to drive vehicle
Diagnostic code No.06
Diagnostic tool displayDisplays the coolant temperature.
ProcedureCompare the actually measured coolant temperature with the
Yamaha diagnostic tool display value.
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation of service
completion
1 Connection of coolant tem-
perature sensor coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected 
Connect the coupler securely
or repair/replace the wire har-
ness.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 2.
2 Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected 
Connect the coupler securely
or repair/replace the wire har-
ness.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 3.
3 Wire harness continuity. Open or short circuit  Re-
place the wire harness.
Between coolant temperature
sensor coupler and ECU cou-
pler.
green/white–green/white
black/blue–black/bluePush the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 4.
4 Installed condition of coolant
temperature sensor.
Check for looseness or
pinching.Improperly installed sensor
 Reinstall or replace the
sensor.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 5.

FUEL INJECTION SYSTEM
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TIP
• Make sure that the engine is completely cool before checking the intake air temperature sensor.
• Before troubleshooting, disconnect the starter motor lead from the starter relay. 5 Defective coolant tempera-
ture sensor.Execute the diagnostic mode.
(Code No. 06)
When engine is cold:
Displayed temperature is
close to the ambient temper-
ature.
The displayed temperature is
not close to the ambient tem-
perature.  Check the cool-
ant temperature sensor.
Replace if defective.
Refer to “CHECKING THE
COOLANT TEMPERATURE
SENSOR” on page 9-78.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 6.
6 Malfunction in ECU. Replace the ECU.
Fault code No. 22
Item Intake air temperature sensor: open or short circuit detected.
Fail-safe systemAble to start engine
Able to drive vehicle
Diagnostic code No.05
Diagnostic tool displayDisplays the intake air temperature.
ProcedureCompare the actually measured intake air temperature with the
Yamaha diagnostic tool display value.
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation of service
completion
1 Connection of intake air tem-
perature sensor coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected 
Connect the coupler securely
or repair/replace the wire har-
ness.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 2.
2 Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected 
Connect the coupler securely
or repair/replace the wire har-
ness.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 3. Fault code No. 21
Item Coolant temperature sensor: open or short circuit detected.

FUEL INJECTION SYSTEM
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TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay. 3 Wire harness continuity. Open or short circuit  Re-
place the wire harness.
Between intake air tempera-
ture sensor coupler and ECU
coupler.
black/blue–black/blue
brown/white–brown/whitePush the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 4.
4 Installed condition of intake
air temperature sensor.
Check for looseness or
pinching.Improperly installed sensor
 Reinstall or replace the
sensor.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 5.
5 Defective intake air tempera-
ture sensor.Execute the diagnostic mode.
(Code No. 05)
When engine is cold:
Displayed temperature is
close to the ambient temper-
ature.
The displayed temperature is
not close to the ambient tem-
perature.  Check the intake
air temperature sensor.
Replace if defective.
Refer to “CHECKING THE
INTAKE AIR TEMPERA-
TURE SENSOR” on page 9-
80.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 6.
6 Malfunction in ECU. Replace the ECU.
Fault code No. 30
Item Latch up detected.
Fail-safe systemUnable to start engine
Unable to drive vehicle
Diagnostic code No.08
Diagnostic tool displayLean angle sensor output voltage
• 0.4–1.4 (upright)
• 3.7–4.4 (overturned)
ProcedureRemove the lean angle sensor and incline it more than 45 degrees.
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation of service
completion
1 The vehicle has overturned. Raise the vehicle upright. Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 2. Fault code No. 22
Item Intake air temperature sensor: open or short circuit detected.