Yamaha YZ 2017 Series, Owner'S Service Manual, Page: 340 / 410

FUEL INJECTION SYSTEM
8-36
2 Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).
Improperly connected

Connect the coupler securely
or repair/replace the wire har-
ness.
Push the start switch.
Fault code number is not dis-
played

Service is finished.
Fault code number is dis-
played

Go to item 3.
3 Wire harness continuity. Open or short circuit

Re-
place the wire harness.
Between throttle position
sensor coupler and ECU cou-
pler.
black/blue–black/blue
yellow–yellow
blue–blue
Push the start switch.
Fault code number is not dis-
played

Service is finished.
Fault code number is dis-
played

Go to item 4.
4 Installed condition of throttle
position sensor.
Check for looseness or
pinching.
Improperly installed sensor

Reinstall or replace the
sensor.
Refer to “ADJUSTING THE
THROTTLE POSITION SEN-
SOR” on page 7-11.
Push the start switch.
Fault code number is not dis-
played

Service is finished.
Fault code number is dis-
played

Go to item 5.
5 Applied voltage of throttle po-
sition sensor lead.
Check the applied voltage.
(black/blue–blue)
Refer to “CHECKING THE
THROTTLE POSITION SEN-
SOR” on page 8-74.
Push the start switch.
Fault code number is not dis-
played

Service is finished.
Fault code number is dis-
played

Go to item 6.
Location of discon-
nected lead
Output
voltage
Disconnected
ground lead
5V
Disconnected out-
put lead
0V
Disconnected
power supply lead
0V
6 Defective throttle position
sensor.
Check throttle position sen-
sor signal.
Execute the diagnostic mode.
(Code No. 01)
When the throttle valve is fully
closed:
A value of 11–14 is indicated.
When throttle valve is fully
open:
A value of 109–116 is indicat-
ed.
An indicated value is out of
the specified range.

Re-
place the throttle position
sensor.
Push the start switch.
Fault code number is not dis-
played

Service is finished.
Fault code number is dis-
played

Go to item 7.
Fault code No. 15
Item Throttle position sensor: open or short circuit detected.