Yamaha MBK MW125 2014, Service Manual

Page: 326 / 380

FUEL INJECTION SYSTEM
8-29
The engine operation is not normal, but the engine trouble warning light does not come on.
1. Check the operation of the following sensors and actuators in the diagnostic mode. Refer to “TROU-
BLESHOOTING DETAILS” on page 8-30.
If a malfunction is detected in the sensors or actuators, repair or replace all faulty parts.
If no malfunction is detected in the sensors and actuators, check and repair the inner parts of the
engine.
EAS30951
YAMAHA DIAGNOSTIC TOOL
This model uses the Yamaha diagnostic tool to identify malfunctions.
For information about using the Yamaha diagnostic tool, refer to the operation manual that is included
with the tool.
Features of the Yamaha diagnostic tool
You can use the Yamaha diagnostic tool to identify malfunctions quicker than with conventional meth-
ods.
By connecting the adapter interface, which is connected to the USB port of a computer, to a vehicle’s
ECU using the communication cable, you can display information that is necessary for identifying mal-
functions and for maintenance to display on the computer. The displayed information includes the sen-
sor output data and information recorded in the ECU.
Functions of the Yamaha diagnostic tool
However, the diagnostic tool cannot be used to freely change the basic vehicle functions, such as ad-
justing the ignition timing.
Connecting the Yamaha diagnostic tool
Disconnect the Yamaha diagnostic tool connector, and then connect the Yamaha diagnostic tool to the
connector “1”.
01: Throttle position sensor signal (throttle angle)
30: Ignition coil
36: Injector
Yamaha diagnostic tool
90890-03231
Fault diagnosis mode: Fault codes recorded on the ECU are read, and the contents are dis-
played.
Function diagnostic mode: Check the operation of the output value of each sensor and actuator.
Inspection mode: Determine whether each sensor or actuator is functioning properly.
CO adjustment mode: Adjust the concentration of CO admissions during idling.
Monitoring mode: Displays a graph of sensor output values for actual operating condi-
tions.
Logging mode: Records and saves the sensor output value in actual driving conditions.
View log: Displays the logging data.
ECU rewrite: If necessary, the ECU is rewritten using ECU rewrite data provided by
Yamaha.
Ignition timing adjustment, etc. cannot be changed from the vehicle’s
original state.