2016 YAMAHA WR 450F check engine

FUEL INJECTION SYSTEM
9-38
TIP
• If fault code Nos. 13 and 14 are both displayed, perform the checks and maintenance jobs for fault
code No. 13 first.
• Before troubleshooting, disconnect the star ter 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
Item Intake air pressure sensor: hose system malfunction (clogged
or detached hose).
Fail-safe system Able to start engine
Able to drive vehicle
Diagnostic code No. 03
Diagnostic tool display Displays the intake air pressure.
Procedure Operate the throttle while pushing the start switch.(If the display
value changes, the performance is OK.)
Item Probable cause of malfunc-
tion and check Maintenance 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
9-39
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 system Able to start engine
Able to drive vehicle
Diagnostic code No. 01
Diagnostic tool display Throttle 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.
Item Probable cause of malfunc-
tion and check Maintenance 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
Item Intake air pressure sensor: hose system malfunction (clogged
or detached hose).

FUEL INJECTION SYSTEM
9-41
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay.
7 Malfunction in ECU. Replace the ECU.
Fault code No. 16
Item
Throttle position sensor: stuck throttle position sensor is de-
tected.
Fail-safe system Able to start engine
Able to drive vehicle
Diagnostic code No. 01
Diagnostic tool display Throttle 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.
Item Probable cause of malfunc-
tion and check Maintenance jobConfirmation of service
completion
1 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 2.
2 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 3.
3 Malfunction in ECU. Replace the ECU. Fault code No. 15
Item Throttle position sensor: open or short circuit detected.

FUEL INJECTION SYSTEM
9-42
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 system Able to start engine
Able to drive vehicle
Diagnostic code No. 06
Diagnostic tool display Displays the coolant temperature.
Procedure Compare the actually measured coolant temperature with the
Yamaha diagnostic tool display value.
Item Probable cause of malfunc-
tion and check Maintenance 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/blue Push 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
9-43
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 system Able to start engine
Able to drive vehicle
Diagnostic code No. 05
Diagnostic tool display Displays the intake air temperature.
Procedure Compare the actually measured intake air temperature with the
Yamaha diagnostic tool display value.
Item Probable cause of malfunc-
tion and check Maintenance 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
9-44
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/white Push 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 system Unable to start engine
Unable to drive vehicle
Diagnostic code No. 08
Diagnostic tool display Lean angle sensor output voltage
• 0.4–1.4 (upright)
• 3.7–4.4 (overturned)
Procedure Remove the lean angle sensor and incline it more than 45 degrees.
Item Probable cause of malfunc-
tion and check Maintenance 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.

FUEL INJECTION SYSTEM
9-45
2 Installed condition of lean an-gle sensor. Check the installed direction
and condition of 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 3.
3 Defective lean angle sensor. Execute the diagnostic mode. (Code No. 08)
Replace if defective.
Refer to “CHECKING THE
LEAN ANGLE SENSOR” on
page 9-75.Push the start switch.
Fault code number is not dis-
played
 Service is finished.
Fault code number is dis-
played  Go to item 4.
4 Malfunction in ECU. Replace the ECU.
Fault code No. 33
Item Ignition coil: open or short circuit detected in the primary lead
of the ignition coil.
Fail-safe system Unable to start engine
Unable to drive vehicle
Diagnostic code No. 30
Actuation Actuates the ignition coil five times at one-second intervals.
The engine trouble warning light and the “WARNING” on the
Yamaha diagnostic tool screen come on each time the ignition coil
is actuated.
Procedure Check that a spark is generated five times.
• Connect an ignition checker.
Item Probable cause of malfunc-
tion and check Maintenance jobConfirmation of service
completion
1 Connection of ignition coil 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. 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.
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. 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 3.
Fault code No.
30
Item Latch up detected.

FUEL INJECTION SYSTEM
9-46
3 Connection of sub wire har-ness coupler.Check the lock-
ing condition of the
coupler.Disconnect the cou-
pler and check the pins (bent
or broken terminals and lock-
ing condition of the pins). Improperly connected

Connect the coupler secure-
lyor repair/replace the sub
wire harness. 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 4.
4 Wire harness continuity. Open or short circuit  Re-
place the wire harness.
Between ignition coil coupler
and ECU coupler.
orange–orange 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 5.
5 Installed condition of ignition coil.
Check for looseness or
pinching. Improperly installed sensor

Reinstall or replace the
sensor. 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 6.
6 Defective ignition coil. (test the primary coils for continu-
ity) Check the ignition coil.
Replace if defective.
Refer to “CHECKING THE
IGNITION COIL” on page 9-
74. 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 7.
7 Malfunction in ECU. Execute the diagnostic mode (diagnostic code No. 30).
No spark  Replace the
ECU.
Fault code No. 33
Item
Ignition coil: open or short circuit detected in the primary lead
of the ignition coil.