Yamaha WR450FN 2022 Owner's Service Manual page 340

Fault code No. 22
TIP
• Make sure that the machine is completely cold before checking the intake air temperature sensor.
• Before troubleshooting, disconnect the starter motor lead from the starter relay.
Fault code No.
Item
Fail-safe system
Diagnostic code No.
Diagnostic tool display
Procedure
Probable cause of malfunc-
Item
tion and check
1 Connection of intake air temper-
ature sensor coupler.
Check the locking condition of
the coupler.
Disconnect the coupler, and
check the pins (for bent or bro-
ken terminals and locking condi-
tion of the pins).
2 Connection of wire harness
ECU coupler.
Check the locking condition of
the coupler.
Disconnect the coupler, and
check the pins (for bent or bro-
ken terminals and locking condi-
tion of the pins).
3 Wire harness continuity.
4 Mounted condition of intake air
temperature sensor.
Check for looseness or pinch-
ing.
Check the mounted position for
correctness.
22
Intake air temperature sensor: open or short circuit detected.
Able to start engine
Able to drive vehicle
05
Displays the intake air temperature.
Compare the actually measured intake air temperature with the Yamaha
diagnostic tool display value.
Maintenance job
Improperly connected  Con-
nect the coupler securely, or
repair/replace the wire harness.
Improperly connected  Con-
nect the coupler securely, or
repair/replace the wire harness.
Open or short circuit  Replace
the wire harness.
Between intake air temperature
sensor coupler and ECU cou-
pler.
brown/white–brown/white
black/blue–black/blue
Improperly mounted sensor 
Remount or replace the sensor.
8-41
FUEL INJECTION SYSTEM
Confirmation of service com-
pletion
Push the start switch (main
relay ON), and then check the
condition of the fault code using
the malfunction mode of the
Yamaha diagnostic tool.
Condition is "Recovered"  Go
to item 7 and finish the service.
Condition is "Detected"  Go to
item 2.
Push the start switch (main
relay ON), and then check the
condition of the fault code using
the malfunction mode of the
Yamaha diagnostic tool.
Condition is "Recovered"  Go
to item 7 and finish the service.
Condition is "Detected"  Go to
item 3.
Push the start switch (main
relay ON), and then check the
condition of the fault code using
the malfunction mode of the
Yamaha diagnostic tool.
Condition is "Recovered"  Go
to item 7 and finish the service.
Condition is "Detected"  Go to
item 4.
Push the start switch (main
relay ON), and then check the
condition of the fault code using
the malfunction mode of the
Yamaha diagnostic tool.
Condition is "Recovered"  Go
to item 7 and finish the service.
Condition is "Detected"  Go to
item 5.