Yamaha MBK MW125 2014, Service Manual

Page: 332 / 380

FUEL INJECTION SYSTEM
8-35
Fault code No. 16
2 Connection of wire harness
ECU coupler.
Check the locking condition of
the coupler.
Disconnect the coupler and
check the pins (bent or broken
terminals and locking condition
of the pins). Improperly connected
→
Con-
nect the coupler securely or re-
place the wire harness.
Turn the main switch to “ON”.
Fault code number is not dis-
played
→
Service is finished.
Fault code number is displayed
→
Go to item 3.
3 Wire harness continuity. Open or short circuit
→
Replace
the wire harness.
Between throttle body sensor
assembly coupler and ECU
coupler.
black/blue–black/blue
yellow–yellow
blue–blue
Turn the main switch to “ON”.
Fault code number is not dis-
played
→
Service is finished.
Fault code number is displayed
→
Go to item 4.
4 Installed condition of throttle
body sensor assembly.
Check for looseness or pinch-
ing. Improperly installed sensor
→
Reinstall sensor.
Turn the main switch to “ON”.
Fault code number is not dis-
played
→
Service is finished.
Fault code number is displayed
→
Go to item 5.
5 Defective throttle position sen-
sor. Check throttle position sensor
signal.
Execute the diagnostic mode.
(Code No. 01)
When the throttle valve is fully
closed:
A value of 14–20 is indicated.
When throttle valve is fully
open:
A value of 97–107 is indicated.
An indicated value is out of the
specified range
→
Replace the
throttle body.
Turn the main switch to “ON”.
Fault code number is not dis-
played
→
Service is finished.
Fault code number is displayed
→
Go to item 6.
6 Malfunction in ECU. Replace the ECU.
Refer to “REPLACING THE
ECU (engine control unit)” on
page 8-59.
Fault code No. 15
Item Throttle position sensor: open or short circuit detected.
Fault code No. 16
Item Throttle position sensor is stuck.
Fail-safe system
Able to start engine
Able to drive vehicle
Diagnostic code No. 01
Tool display
Throttle position sensor signal
• 14–20 (Fully closed position)
• 97–107 (Fully open position)
Procedure
• Check with throttle valve fully closed.
• Check with throttle valve fully open.
Item
Probable cause of malfunc-
tion and check
Maintenance job
Confirmation of service com-
pletion