Yamaha MBK MW125 2014, Service Manual

Page: 347 / 380

FUEL INJECTION SYSTEM
8-50
3 Air leak in intake air passages. Check the intake air passages
for air leaks. Start the engine and let it idle
for approximately 10 seconds.
Fault code number is not dis-
played
→
Service is finished.
Fault code number is displayed
→
Go to item 4.
4 Throttle valve is not fully closed. Check the throttle body.
Check the throttle cable.
Refer to “CHECKING THE
THROTTLE GRIP OPERA-
TION” on page 3-24.
Start the engine and let it idle
for approximately 10 seconds.
Fault code number is not dis-
played
→
Service is finished.
Fault code number is displayed
→
Go to item 5.
5 Installed condition of ISC valve. Check for looseness or pinch-
ing.
Improperly installed ISC valve
→
Reinstall or replace the ISC
valve.
Refer to “CLEANING THE ISC
(IDLE SPEED CONTROL)
UNIT AND THROTTLE BODY”
on page 7-9.
Start the engine and let it idle
for approximately 10 seconds.
Fault code number is not dis-
played
→
Service is finished.
Fault code number is displayed
→
Go to item 6.
6 Installed condition of throttle
body sensor assembly. Check for looseness or pinch-
ing. Start the engine and let it idle
for approximately 10 seconds.
Fault code number is not dis-
played
→
Service is finished.
Fault code number is displayed
→
Go to item 7.
7 Defective throttle body sensor
assembly. Execute the diagnostic mode.
(Code No. D03)
When engine is stopped: Atmo-
spheric pressure at the current
altitude and weather conditions
is indicated.
At sea level: Approx. 101 kPa
1000 m above sea level: Ap-
prox. 90 kPa
2000 m above sea level: Ap-
prox. 80 kPa
3000 m above sea level: Ap-
prox. 70 kPa
When engine is cranking: Make
sure that the indication value
changes.
The value does not change
when engine is cranking
→
Re-
place the throttle body.
Execute the diagnostic mode.
(Code No. D01).
When throttle is fully closed: A
value of 14–20 is indicated.
When throttle is fully open: A
value of 92–102 is indicated.
If the indication is outside of
range
→
Replace the throttle
body.
Start the engine and let it idle
for approximately 10 seconds.
Fault code number is not dis-
played
→
Service is finished.
Fault code number is displayed
→
Go to item 8.
Fault code No. 79
Item
Engine speed is high when the Engine is idling.
Deceleration is poor when the vehicle is ridden.
Bad condition of engine or sensor.