Yamaha MBK MW125 2014, Service Manual

Page: 345 / 380

FUEL INJECTION SYSTEM
8-48
Fault code No. 50
Fault code No. 61
Fault code No. 50
Item
Faulty ECU memory. (When this malfunction is detected in the ECU,
the fault code number might not appear on the tool display.)
Fail-safe system
Unable to start engine
Unable to drive vehicle
Diagnostic code No. —
Tool display —
Procedure —
Item
Probable cause of malfunc-
tion and check
Maintenance job
Confirmation of service com-
pletion
1 Malfunction in ECU. Replace the ECU.
Refer to “REPLACING THE
ECU (engine control unit)” on
page 8-59. Turn the main switch to “ON”.
Check that the fault code num-
ber is not displayed.
Fault code No. 61
Item ISC (idle speed control) unit: open or short circuit detected.
Fail-safe system
Able to start engine
Able to drive vehicle
Diagnostic code No. 54
Action
The ISC (idle speed control) valve fully closes, and then it turn back fully
opens.
This operation takes approximately 3 seconds.
Procedure Check that ISC valve is actuated by listening for the operating sound.
Item
Probable cause of malfunc-
tion and check
Maintenance job
Confirmation of service com-
pletion
1 Connection of ISC valve cou-
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). Improperly connected
→
Con-
nect the coupler securely or re-
place the wire harness.
Set the main switch to “ON”.
Fault code number is not dis-
played
→
Service is fin-
ished.Fault code number is
displayed
→
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 (bent or broken
terminals and locking condition
of the pins). Improperly connected
→
Con-
nect the coupler securely or re-
place the wire harness.
Set the main switch to “ON”.
Fault code number is not dis-
played
→
Service is fin-
ished.Fault code number is
displayed
→
Go to item 3.