Yamaha Wr250r 2008 Manual

 
FUEL INJECTION SYSTEM 
8-30 
1. AC magneto
3. Main switch
4. Battery
5. Main fuse
6. Starter relay
8.  Right handlebar switch
9.  Engine stop switch
10. Start switch
11. Relay unit
12. Sidestand switch
13. Neutral switch
14. Clutch switch
15. Fuel pump
16. ECU
17. Ignition coil
18. Spark plug
19. ITS solenoid
20. Fuel injector
21. AI solenoid
22. Intake air temperature sensor
23. Coolant temperature sensor
24. Speed sensor
25. Throttle position sensor
26. Intake air pressure sensor
27. Lean angle...

 
FUEL INJECTION SYSTEM 
8-31 
EAS27350 
ECU SELF-DIAGNOSTIC FUNCTION 
The ECU is equipped with a self-diagnostic function in order to ensure that the fuel injection system is
operating normally. If this function detects a malfunction in the system, it immediately operates the en-
gine under substitute characteristics and illuminates the engine trouble warning light to alert the rider
that a malfunction has occurred in the system. Once a malfunction has been detected, a fault code is
stored in the memory...

 
FUEL INJECTION SYSTEM 
8-32 
EAS27393 
FAIL-SAFE ACTIONS (SUBSTITUTE CHARACTERISTICS OPERATION CONTROL) 
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...

 
FUEL INJECTION SYSTEM 
8-33 
Communication error with the multifunction meter 
* If multiple malfunctions have been detected for the ECU, you may not be able to start or drive the vehicle. 44Error in writing the 
amount of CO adjust-
ment on EEPROMError is detected while reading or writ-
ing on EEPROM (code re-registering 
key code and throttle valve fully 
closed notification value).Able Able
46Vehicle system power 
supply
(Monitor voltage)Power supply to the ECU system relay 
is not normal.Able Able...

 
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 meter.
b. Identify the system with the malfunction. Re-
fer to “Self-Diagnostic Function table”.
c. Identify the probable cause of malfunction.
Refer to “Diagnostic monitoring code table”.

 
2. Checking and repair...

 
FUEL INJECTION SYSTEM 
8-35 
bers.
8. Verify the operation of the sensor or actuator. 
 
Sensor operation
The data representing the operating condi-
tions of the sensor appears on the trip LCD. 
 
Actuator operation
Set the engine stop switch to “ON” to operate
the actuator.
NOTE:
 
If the engine stop switch is set to “ON”, set it to 
“OFF”, and then set it to “ON” again.
9. Turn the main switch to “OFF” to cancel the
diagnostic mode. 

 
FUEL INJECTION SYSTEM 
8-36 
Diagnostic code table 
Fault 
code 
No.Symptom Probable cause of malfunctionDiagnostic 
code No.  
12No normal signals are 
received from the crankshaft 
position sensor. 
 
Open or short circuit in wire harness. 
 
Defective crankshaft position sensor. 
 
Malfunction in pickup rotor. 
 
Malfunction in ECU. 
 
Improperly installed sensor. 
—
13Intake air pressure sen-
sor-open or short circuit 
detected. 
 
Open or short circuit in wire harness. 
 
Defective intake...

 
FUEL INJECTION SYSTEM 
8-37 
Sensor operation table 
42No normal signals are 
received from the speed sen-
sor. 
 
Open or short circuit in wiring harness. 
 
Defective speed sensor. 
 
Malfunction in vehicle speed sensor 
detected unit. 
 
Malfunction in ECU. 
07
Open or short circuit in neutral 
switch. 
 
Open circuit in wire harness. 
 
Defective neutral switch. 
 
ECU is defective. 
21
43Supply power to the fuel injec-
tor and fuel pump is not nor-
mal. 
 
Open circuit in wire harness. 
...

 
FUEL INJECTION SYSTEM 
8-38 
03 Pressure difference
(atmospheric pressure-intake 
air pressure)Displays the intake air pressure.
Set “” the engine stop 
switch, and then push the 
start switch. (If the display 
value changes, the perfor-
mance is OK.)
05 Intake air temperature Displays the intake air tempera-
ture.Compare the actually mea-
sured intake air temperature 
with the meter display value. 
(*1)
06 Coolant temperature Displays the coolant tempera-
ture.Compare the actually mea-
sured coolant...

 
FUEL INJECTION SYSTEM 
8-39 
*1 If it is not possible to check the intake temperature, use the ambient temperature as reference (use
the compared values for reference). 
Actuator operation table 
61 Malfunction history code dis-
play— 
 
No history 00 
 
History exists 12 
– 
70 (Fault detection code) 
 
(If code numbers more 
than one are detected, the 
display alternates every 
two seconds to show all the 
detected code numbers. 
When all code numbers are 
shown, the display repeats 
the same...