Yamaha MBK MW125 2014 Service Manual page 341

Fault code No. 39
Fault code No.
Item
Fail-safe system
Diagnostic code No.
Actuation
36
Procedure
Probable cause of malfunc-
Item
tion and check
1 Connection of injector 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 Defective injector.
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 Malfunction in ECU.
6 Delete the fault code.
39
Injector: open or short circuit detected.
Unable to start engine
Unable to drive vehicle
36
Actuates injector five times at one-second intervals.
Illuminates the engine trouble warning light.
Check that injector is actuated five times by listening for the operating
sound.
Maintenance job
Improperly connected → Con-
nect the coupler securely or re-
place the wire harness.
Measure the injector resistance.
Replace if out of specification.
Refer to "CHECKING THE
FUEL INJECTORS" on page
8-67.
Improperly connected → Con-
nect the coupler securely or re-
place the wire harness.
Open or short circuit → Replace
the wire harness.
Between injector coupler and
ECU coupler.
Injector
orange/black–orange/black
Between injector coupler and
signaling system fuse terminal.
red/blue–red/blue
Replace the ECU.
Refer to "REPLACING THE
ECU (engine control unit)" on
page 8-59.
8-44
FUEL INJECTION SYSTEM
Confirmation of service com-
Execute the diagnostic mode.
(Code Nos. 36)
No operating sound → Go to
item 2.
Operating sound → Go to item
6.
Execute the diagnostic mode.
(Code Nos. 36)
No operating sound → Go to
item 3.
Operating sound → Go to item
6.
Execute the diagnostic mode.
(Code Nos. 36)
No operating sound → Go to
item 4.
Operating sound → Go to item
6.
Execute the diagnostic mode.
(Code Nos. 36)
No operating sound → Go to
item 5.
Operating sound → Go to item
6.
Start the engine and let it idle
for approximately 5 seconds.
Check that the fault code num-
ber is not displayed.
pletion