Yamaha YZ450FP 2023, Owner'S Service Manual, Page: 323 / 388

FUEL INJECTION SYSTEM
8-24
Fault code No. 14
TIP
If fault code numbers 13 and 14 are both displayed, perform checkup and repair jobs for fault code num-
ber 13 first.
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 The atmospheric pressure is displayed on the Yamaha diagnostic tool.
Item
Probable cause of malfunc-
tion and check
Maintenance job
Confirmation of service com-
pletion
1 The intake air pressure sensor
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 (fully
close the throttle valve).
Check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is “Recovered”

Go
to item 3 and finish the service.
Condition is “Detected”

Go to
item 2.
2 Defective intake air pressure
sensor.
Execute the diagnostic mode.
(Code No. 03)
Proper display:
Atmospheric pressure at the
current altitude and weather
conditions is indicated while
engine stopping.
0 m above sea level: About 101
kPa (about 3.63 V)
1000 m above sea level: About
90 kPa (about 3.30 V)
2000 m above sea level: About
80 kPa (about 3.00 V)
3000 m above sea level: About
70 kPa (about 2.70 V)
Value does not change during
cranking

Intake air pressure
sensor replacement.
Start the engine and let it idle for
approximately 5 seconds (fully
close the throttle valve).
Check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is “Recovered”

Go
to item 3 and finish the service.
3 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.