Yamaha WR125R 2009, Service Manual

Page: 319 / 372

FUEL INJECTION SYSTEM
8-34
EAS27400
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 FI diagnostic tool.
b. Identify the system with the fault code. Refer
to “Self-Diagnostic Function table”.
c. Identify the probable cause of the malfunc-
tion. Refer to “Diagnostic code table”.
▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲▲▲
2. Check and repair the probable cause of the
malfunction.
3. Perform fuel injection system reinstatement
action.
Refer to “Reinstatement method” of table in
“TROUBLESHOOTING DETAILS” on page
8-42.
4. Set the main switch to “OFF”, then to “ON”
again, and then check that no fault code num-
ber is displayed.
TIP
If another fault code is displayed, repeat steps
(1) to (4) until no fault code number is displayed.
5. Erase the malfunction history in the diagnos-
tic mode. Refer to “Sensor operation table
(Diagnostic code No. D62)”.
TIP
Setting the main switch to “OFF” will not erase
the malfunction history.
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 “Sensor operation table” and “Actuator op-
eration table”.
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.
EAS27431
DIAGNOSTIC MODE
It is possible to monitor the sensor output data or check the activation of actuators with the FI diagnostic
tool connected to the vehicle and set to the normal mode or the diagnostic monitoring mode.
50
ECU internal malfunc-
tion
(memory check error)
Faulty ECU memory. (When this
malfunction is detected in the
ECU, the fault code number might
not appear on the FI diagnostic
tool.)
Unable Unable
— Start unable warning
Engine trouble warning light flash-
es when the start switch is
pushed.
Unable Unable
Fault
code No.
Item Symptom
Able / un-
able to start
Able / un-
able to
drive
Fault code No. No fault code No.
Check and repair.
Refer to “TROUBLE-
SHOOTING DE-
TAILS” on page 8-42.
Monitor the opera-
tion of the sensors
and actuators in the
diagnostic mode. Re-
fer to “Sensor opera-
tion table” and
“Actuator operation
table”. Check and repair.
Refer to “Self-Diag-
nostic Function ta-
ble”.
30: Ignition coil
36: Fuel injector