Yamaha MBK MW125 2014 Service Manual page 337

Fault code No.
Item
Probable cause of malfunc-
Item
tion and check
1 Installed condition of O
2 Connection of O
pler.
Check the locking condition of
the coupler.
Disconnect the coupler and
check the pins (bent or broken
terminals and locking condition
of the pins).
3 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).
4 Wire harness continuity.
5 Check fuel pressure.
6 Defective O sensor.
2
7 Malfunction in ECU.
Fault code No. 30
Fault code No.
Item
Fail-safe system
24
O sensor: no normal signals are received from the O
2
sensor. Improperly installed sensor →
2
Reinstall or replace the sensor.
Improperly connected → Con-
sensor cou-
2
nect the coupler securely or re-
place the wire harness.
Improperly connected → Con-
nect the coupler securely or re-
place the wire harness.
Open or short circuit → Replace
the wire harness.
Between O
ECU coupler.
gray/red–gray/red
Refer to "CHECKING THE
FUEL PRESSURE" on page
7-3.
Check the O
Replace if defective.
Refer to "ENGINE REMOVAL"
on page 5-3.
Replace the ECU.
Refer to "REPLACING THE
ECU (engine control unit)" on
page 8-59.
30
Latch up detected.
Unable to start engine
Unable to drive vehicle
FUEL INJECTION SYSTEM
Maintenance job
sensor coupler and
2
sensor.
2
8-40
sensor.
2
Confirmation of service com-
pletion
Start the engine, warm it up,
and then race it.
Fault code number is not dis-
played → Service is finished.
Fault code number is displayed
→ Go to item 2.
Start the engine, warm it up,
and then race it.
Fault code number is not dis-
played → Service is finished.
Fault code number is displayed
→ Go to item 3.
Start the engine, warm it up,
and then race it.
Fault code number is not dis-
played → Service is finished.
Fault code number is displayed
→ Go to item 4.
Start the engine, warm it up,
and then race it.
Fault code number is not dis-
played → Service is finished.
Fault code number is displayed
→ Go to item 5.
Start the engine, warm it up,
and then race it.
Fault code number is not dis-
played → Service is finished.
Fault code number is displayed
→ Go to item 6.
Start the engine, warm it up,
and then race it.
Fault code number is not dis-
played → Service is finished.
Fault code number is displayed
→ Go to item 7.