Yamaha YZ450FP 2023, Owner'S Service Manual

Page: 324 / 388

FUEL INJECTION SYSTEM
8-25
Fault code No. 15
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay.
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
Displays the throttle angle.
•
11–14 (throttle in fully closed position)
•
86–92 (throttle in fully opened position)
Procedure
•
Check with throttle fully closed.
•
Check with throttle fully opened.
Item
Probable cause of malfunc-
tion and check
Maintenance job
Confirmation of service com-
pletion
1 Connection of throttle position
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).
Improperly connected

Con-
nect the coupler securely, or
repair/replace the wire harness.
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 2.
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).
Improperly connected

Con-
nect the coupler securely, or
repair/replace the wire harness.
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 3.
3 Wire harness continuity. Open or short circuit

Replace
the wire harness.
Between throttle position sensor
coupler and ECU coupler.
yellow–yellow
blue–blue
Between throttle position sensor
coupler and joint connector.
black–black
Between joint connector and
ECU coupler.
black/blue–black/blue
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 4.
4 Mounted condition of throttle
position sensor.
Check for looseness or pinch-
ing.
Check the mounted position for
correctness.
Improperly mounted sensor

Remount or replace the sensor.
Refer to “ADJUSTING THE
THROTTLE POSITION SEN-
SOR” on page 7-8.
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 5.