Yamaha YZ450FP 2023 Owner's Service Manual page 325

Fault code No.
Item
5 Applied voltage of throttle posi-
tion sensor lead.
6 Defective throttle position sen-
sor.
7 Faulty ECU.
8 Delete the fault code.
Fault code No. 16
TIP
• If fault code numbers 15 and 16 are both displayed, perform checkup and repair jobs for fault code
number 15 first.
• 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
15
Throttle position sensor: open or short circuit detected.
Check the applied voltage.
(black–blue)
Location of discon-
nected lead
Disconnected
ground lead
Disconnected output
lead
Disconnected power
supply lead
Execute the diagnostic mode.
(Code No. 01)
Correct display range:
When the throttle is fully closed,
11–14 displays.
When the throttle is fully
opened, 86–92 displays.
Incorrect display range 
Replace the throttle position
sensor, and then reset the ECU
using the diagnostic code num-
ber "87".
Refer to "DIAGNOSTIC CODE:
SENSOR OPERATION TABLE"
on page 9-12.
Replace the ECU.
Confirm that the fault code has
a condition of "Recovered"
using the Yamaha diagnostic
tool, and then delete the fault
code.
16
Throttle position sensor: stuck throttle position sensor is detected.
Able to start engine
Able to drive vehicle
01
Displays the throttle angle.
• 11–14 (throttle in fully closed position)
• 86–92 (throttle in fully opened position)
• Check with throttle fully closed.
• Check with throttle fully opened.
Maintenance job
8-26
FUEL INJECTION SYSTEM
Start switch to ON (no need to
start the engine), and then
check the condition of the fault
Output
code using the malfunction
voltage
mode of the Yamaha diagnostic
tool.
5 V
Condition is "Recovered"  Go
to item 8 and finish the service.
Condition is "Detected"  Go to
0 V
item 6.
0 V
Start switch to ON (no need to
start the engine), and then
check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is "Recovered"  Go
to item 8 and finish the service.
Condition is "Detected"  Go to
item 7.
Service is finished.
Confirmation of service com-
pletion