Yamaha YZ450FN 2022, Owner'S Service Manual, Page: 309 / 366

FUEL INJECTION SYSTEM
8-28
Fault code No. 30
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay.
5 Defective intake air tempera-
ture sensor.
Execute the diagnostic mode.
(Code No. 05)
When the machine is cold, dis-
played temperature is close to
the ambient temperature.
Improper display

Replace the
intake air temperature sensor.
Start switch to ON (main relay
ON), and then check the condi-
tion 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 6.
6 Faulty ECU. Replace the ECU. Service is finished.
7 Delete the fault code. Confirm that the fault code has
a condition of “Recovered”
using the Yamaha diagnostic
tool, and then delete the fault
code.
Fault code No. 30
Item The vehicle has overturned.
Fail-safe system
Unable to start engine
Unable to drive vehicle
Diagnostic code No.
08
Diagnostic tool display
Displays the lean angle sensor output voltage.
•
0.4–1.4 (V) (upright)
•
3.7–4.4 (V) (overturned)
Procedure
Remove the ECU, and incline it 45

or more.
Item
Probable cause of malfunc-
tion and check
Maintenance job
Confirmation of service com-
pletion
1 The vehicle has overturned. Raise the vehicle upright. Start switch to ON (main relay
ON), wait 10 seconds, then
check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is “Recovered”

Go
to item 4 and finish the service.
Condition is “Detected”

Go to
item 2.
2 Mounted condition of ECU.
Check for looseness or pinch-
ing.
Check the mounted condition
for correctness.
Improperly mounted ECU

Remount the ECU.
Start switch to ON (main relay
ON), wait 10 seconds, then
check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is “Recovered”

Go
to item 4 and finish the service.
Condition is “Detected”

Go to
item 3.
Fault code No. 22
Item Intake air temperature sensor: open or short circuit detected.