Yamaha MBK MW125 2014 Service Manual page 333

Fault code No.
Item
1 Installed condition of throttle po-
sition sensor.
2 Defective throttle position sen-
sor.
3 Malfunction in ECU
Fault code No. 19
Fault code No.
Item
Fail-safe system
Diagnostic code No.
Tool display
Procedure
Probable cause of malfunc-
Item
tion and check
1 Connection of sidestand switch
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).
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).
16
Throttle position sensor is stuck.
Check for looseness or pinch-
ing.
Make sure that the mounting
position is corrected.
Execute the diagnostic mode.
(Code No. 01)
When the throttle valve is fully
closed:
A value of 14–20 is indicated.
When the throttle valve is fully
open:
A value of 97–107 is indicated.
Replace the throttle body, if de-
fective.
Replace the ECU.
Refer to "REPLACING THE
ECU (engine control unit)" on
page 8-59.
19
Sidestand switch: a break or disconnection of the blue/yellow lead of
the ECU is detected.
Unable to start engine
Unable to drive vehicle
20
Sidestand switch
• "ON" (sidestand retracted)
• "OFF" (sidestand extended)
Extend and retract the sidestand (with the transmission in gear).
Maintenance job
Improperly connected → Con-
nect the coupler securely or re-
place the wire harness.
Improperly connected → Con-
nect the coupler securely or re-
place the wire harness.
8-36
FUEL INJECTION SYSTEM
Turn the main switch to "ON"
and operate the throttle valve
open and close.
Fault code number is not dis-
played → Service is finished.
Fault code number is displayed
→ Go to item 2.
Turn the main switch to "ON"
and operate the throttle valve
open and close.
Fault code number is not dis-
played → Service is finished.
Fault code number is displayed
→ Go to item 3.
Confirmation of service com-
Turn the main switch to "ON",
and then extend and retract the
sidestand.
Fault code number is not dis-
played → Service is finished.
Fault code number is displayed
→ Go to item 2.
Turn the main switch to "ON",
and then extend and retract the
sidestand.
Fault code number is not dis-
played → Service is finished.
Fault code number is displayed
→ Go to item 3.
pletion