Yamaha MBK MW125 2014, Service Manual

Page: 325 / 380

FUEL INJECTION SYSTEM
8-28
Checking the engine trouble warning light
The engine trouble warning light comes on for around 2 seconds after the main switch has been turned
to “ON” and it comes on while the start switch is being pushed. If the warning light does not come on
under these conditions, the warning light (LED) may be defective.
ECU detects an abnormal signal from a sensor
If the ECU detects an abnormal signal from a sensor while the vehicle is being driven, the ECU illumi-
nates the engine trouble warning light and provides the engine with alternate operating instructions that
are appropriate for the type of malfunction.
When an abnormal signal is received from a sensor, the ECU processes the specified values that are
programmed for each sensor in order to provide the engine with alternate operating instructions that
enable the engine to continue operating or stop operating, depending on the conditions.
EAS30506
TROUBLESHOOTING METHOD
The engine operation is not normal and the engine trouble warning light comes on.
1. Check:
• Fault code number
▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼▼▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼▼▼▼ ▼▼ ▼
a. Check the fault code number displayed on the multi-function meter right display.
b. Identify the faulty system with the fault code number.
c. Identify the probable cause of the malfunction.
▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲▲▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲▲▲ ▲▲▲ ▲
2. Check and repair the probable cause of the malfunction.
3. Perform the reinstatement action for the fuel injection system.
Refer to “Confirmation of service completion” in the appropriate table in “TROUBLESHOOTING DE-
TAILS” on page 8-30.
4. Turn the main switch to “OFF”, and back to “ON”, and then check that no fault code number is dis-
played.
TIP
If another fault code number is displayed, repeat steps (1) to (4) until no fault code number is displayed.
5. Erase the malfunction history in the diagnostic mode (code No. 62). Refer to “SELF-DIAGNOSTIC
FUNCTION AND DIAGNOSTIC CODE TABLE” on page 9-5.
TIP
Turning the main switch to “OFF” will not erase the malfunction history.
Fault code No. No fault code No.
Check and repair. Refer
to “TROUBLESHOOT-
ING DETAILS” on page
8-30.
Monitor the operation of
the sensors and actua-
tors in the diagnostic
mode. Refer to “TROU-
BLESHOOTING DE-
TAILS” on page 8-30
and “SELF-DIAGNOS-
TIC FUNCTION AND
DIAGNOSTIC CODE
TABLE” on page 9-5. Check and repair.