Page 384 of 428

FUEL INJECTION SYSTEM
9-52
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay.
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay. Fault code No. 50
ItemFaulty ECU memory. (When this malfunction is detected in the
ECU, the fault code number might not appear on the meter.)
Fail-safe systemUnable to start engine
Unable to drive vehicle
Diagnostic code No.—
Diagnostic tool display—
Procedure—
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation of service
completion
1 Malfunction in ECU. Replace the ECU. Push the start switch.
Check that the fault code
number is not displayed.
Fault code No. waiting for connection
Item No communication signal is received from the ECU.
Fail-safe systemAble to start engine (Unable when ECU is malfunctioning)
Able to drive vehicle (Unable when ECU is malfunctioning)
Diagnostic code No.—
Diagnostic tool display—
Procedure—
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation of service
completion
1 Connection of Yamaha diag-
nostic tool coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected
Connect the coupler securely
or repair/replace the wire har-
ness.Push the start switch.
Fault code number is not dis-
played Service is finished.
Fault code number is dis-
played Go to item 2.
2 Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected
Connect the coupler securely
or repair/replace the wire har-
ness.Push the start switch.
Fault code number is not dis-
played Service is finished.
Fault code number is dis-
played Go to item 3.
Page 387 of 428

FUEL INJECTION SYSTEM
9-55
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay.
Fault code No. Er-4
ItemRegistered data cannot be received from the Yamaha diagnos-
tic tool.
Fail-safe systemAble to start engine
Able to drive vehicle
Diagnostic code No.—
Diagnostic tool display—
Procedure—
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation of service
completion
1 Connection of Yamaha diag-
nostic tool coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected
Connect the coupler securely
or repair/replace the wire har-
ness.Push the start switch.
Fault code number is not dis-
played Service is finished.
Fault code number is dis-
played Go to item 2.
2 Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected
Connect the coupler securely
or repair/replace the wire har-
ness.Push the start switch.
Fault code number is not dis-
played Service is finished.
Fault code number is dis-
played Go to item 3.
3 Wire harness continuity. Open or short circuit Re-
place the wire harness.
light green–light greenPush the start switch.
Fault code number is not dis-
played Service is finished.
Fault code number is dis-
played Go to item 4.
4 Yamaha diagnostic tool mal-
function.Replace the Yamaha diag-
nostic tool.Push the start switch.
Fault code number is not dis-
played Service is finished.
Fault code number is dis-
played Go to item 5.
5 Malfunction in ECU. Replace the ECU.
Page 389 of 428
FUEL PUMP SYSTEM
9-57
1. Joint connector
2. Joint connector
9. Battery
10.Frame ground
11.Starter relay
12.Main fuse
22.ECU (engine control unit)
26.Fuel pump
30.Joint connector
36.Engine stop switch
48.Frame ground
Page 395 of 428
ELECTRICAL COMPONENTS
9-63
1. Intake air temperature sensor
2. Intake air pressure sensor
3. Throttle position sensor
4. Starter relay
5. Main fuse
6. Headlight relay
7. Starting circuit cut-off relay
8. Lean angle sensor
9. Radiator fan motor fuse
10.Radiator fan motor relay
11.Main relay
12.Coolant temperature sensor
Page 404 of 428

ELECTRICAL COMPONENTS
9-72
EAS2GB7386CHECKING THE RELAYS
Check each switch for continuity with the pock-
et tester. If the continuity reading is incorrect,
replace the relay.
1. Disconnect the relay from the wire harness.
2. Connect the pocket tester ( 1) and bat-
tery (12 V) to the relay terminal as shown.
Check the relay operation.
Out of specification Replace.
Starter relay
Main relayStarting circuit cut-off relay
Headlight relay
Radiator fan motor relay Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
1. Positive battery terminal
2. Negative battery terminal
3. Positive tester probe
4. Negative tester probe
Result
Continuity
(between “3” to “4”)
1. Positive battery terminal
2. Negative battery terminal
3. Positive tester probe
4. Negative tester probe
Result
Continuity
(between “3” to “4”)
21 3
4
R/WBr/WR/YL/G
1 23
4
L/R
BrR
R,R/W
1. Positive battery terminal
2. Negative battery terminal
3. Positive tester probe
4. Negative tester probe
Result
Continuity
(between “3” to “4”)
1. Positive battery terminal
2. Negative battery terminal
3. Positive tester probe
4. Negative tester probe
Result
Continuity
(between “3” to “4”)
1. Positive battery terminal
2. Negative battery terminal
3. Positive tester probe
4. Negative tester probe
1 23
4
G/B
L/B
L/G,L/W
1 23
4
R,R/Y
GR
1 23
4
P/L
R/L
R/W
Br,R/W
Page 423 of 428

LIST OF SELF-DIAGNOSTIC AND FAIL-SAFE ACTIONS
10-8
ACTUATOR OPERATION TABLE
Diag-
nostic
code
No.Item Actuation Procedure
30 Ignition coil Actuates the ignition coil five
times at one-second inter-
vals.
“WARNING” on the Yamaha
diagnostic tool blinks five
times when the ignition coil is
actuated.Check that a spark is gener-
ated five times.
• Connect an ignition
checker.
36 Injector Actuates the injector five
times at one-second inter-
vals.
“WARNING” on the Yamaha
diagnostic tool blinks five
times when the radiator fan
motor relay is actuated.TIP: Before performing
this operation, be sure to
disconnect the fuel pump
coupler.
Check that injector is actu-
ated five times by listening
for the operating sound.
51 Radiator fan motor relay Actuates the radiator fan mo-
tor relay five times at five-sec-
ond intervals.
“WARNING” on the Yamaha
diagnostic tool blinks five
times when the radiator fan
motor relay is actuated.Check that the radiator fan
motor relay is actuated five
times by listening for the op-
erating sound.
52 Headlight relay Actuates the headlight relay
five times at five-second in-
tervals.
“WARNING” on the Yamaha
diagnostic tool blinks five
times when the headlight re-
lay is actuated.Check that the headlight re-
lay is actuated five times by
listening for the operating
sound.
Page 424 of 428

EAS2GB7426
WIRING DIAGRAM
WR250F/WR250FG 2016
1. Joint connector
2. Joint connector
3. Joint connector
4. AC magneto
5. Rectifier/regulator
6. Headlight relay
7. Main relay
8. Engine ground
9. Battery
10. Frame ground
11. Starter relay
12. Main fuse
13. Starter motor
14. Starter relay diode
15. Indicator light
16. Engine trouble warning light
17. Fuel level warning light
18. Resistor
19. Fuel sender
20. Diode
21. Coupler for connecting option-
al part
22. ECU (engine control unit)
23. Ignition coil
24. Spark plug
25. Injector
26. Fuel pump
27. Radiator fan motor relay
28. Radiator fan motor fuse
29. Radiator fan motor
30. Joint connector
31. Intake air temperature sensor
32. Coolant temperature sensor
33. Throttle position sensor
34. Intake air pressure sensor
35. Lean angle sensor
36. Engine stop switch
37. Neutral switch
38. Diode
39. Starting circuit cut-off relay
40. Clutch switch
41. Start switch
42. Joint connector
43. Taillight
44. Headlight
45. Coupler for connecting option-
al switch
46. Speed sensor
47. Multi-function display
48. Frame ground
49. Ignition coil sub-lead
50. Negative battery lead
EAS2GB7427COLOR CODE
BBlack
Br Brown
Ch Chocolate
Dg Dark green
G Green
Gy Gray
LBlue
Lg Light green
O Orange
PPink
RRed
Sb Sky blue
WWhite
Y Yellow
B/L Black/Blue
B/O Black/Orange
B/W Black/White
B/Y Black/Yellow
Br/W Brown/White
G/B Green/Black
G/W Green/White
G/Y Green/Yellow
L/B Blue/Black
L/G Blue/Green
L/R Blue/Red
L/W Blue/White
L/Y Blue/Yellow
P/L Pink/Blue
R/B Red/Black
R/L Red/Blue
R/W Red/White
R/Y Red/Yellow
W/B White/Black
Y/B Yellow/Black
Y/G Yellow/Green
Y/R Yellow/Red