2016 YAMAHA WR 450F ad blue

ELECTRICAL COMPONENTS
9-73
EAS2GC1388CHECKING THE DIODE
1. Check:•DiodeOut of specification  Replace.
TIP
The pocket tester and the analog pocket tester
readings are shown in the following table.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Disconnect the diode from the wire harness.
b. Connect the pocket tester (  1) to the di-
ode coupler as shown.
c. Check the diode for continuity.
d. Check the diode for no continuity.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GC1389CHECKING THE IGNITION SPARK GAP
1. Check: • Ignition spark gapOut of specification  Perform the ignition
system troubleshooting, starting with step 4.
Refer to “TROUBLESHOOTING” on page 9-
4.
TIP
If the ignition spark gap is within specification,
the ignition system circui t is operating normally.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Remove the spark plug cap from the spark
plug.
b. Connect the ignition checker “1” as shown.
c. Push the engine stop switch.
d. Measure the ignition spark gap “a”.
e. Crank the engine by pushing the start switch and gradually increase the spark gap until a
misfire occurs.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GC1390CHECKING THE SPARK PLUG CAP
1. Remove:• Spark plug cap
(from the spark plug lead)
2. Check: • Spark plug cap resistance
Out of specification  Replace.
Result
Continuity
(between “3” to “4”)
Pocket tester 90890-03112
Analog pocket tester YU-03112-C
No continuity Tester positive lead  Sky blue
“1”
Tester negative lead  Green/
Black “2”
Continuity Tester positive lead  Green/
Black “2”
Tester negative lead  Sky blue
“1”
No continuity Tester positive lead  Red “3”
Tester negative lead  Red/Blue
“4”
Continuity Tester positive lead  Red/Blue
“4”
Tester negative lead  Red “3”
2
1
4
3
R
Sb
G/B R/L
Minimum ignition spark gap 6.0 mm (0.24 in)
Ignition checker 90890-06754
Oppama pet–4000 spark checker YM-34487
2. Spark plug cap
Resistance 7.50–12.50 k 

ELECTRICAL COMPONENTS
9-75
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect the pocket tester ( 100) to the
crankshaft position sensor coupler.
b. Measure the crankshaft position sensor re- sistance.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GC1393CHECKING THE LEAN ANGLE SENSOR
1. Remove:• Lean angle sensor
(from the bracket)
2. Check: • Lean angle sensor output voltage
Out of specification  Replace.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect the lean angle sensor coupler to
the wire harness.
b. Connect the pocket tester (DC 20 V) to the
lean angle sensor coupler as shown. c. Incline the lean angle sensor.
d. Measure the lean angle sensor output volt-
age.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GC1394CHECKING THE STARTER MOTOR OPERA-
TION
1. Check:• Starter motor operation
Does not operate  Perform the electric
starting system troubleshooting, starting
with step 4.
Refer to “ELECTRIC STARTING SYSTEM”
on page 9-6.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect the positive battery terminal “1” and starter motor lead “2” with a jumper lead “3”.
EWA
WARNING
• A wire that is used as a jumper lead must
have at least the same capacity of the bat-
tery lead, otherwise the jumper lead may
burn.
• This check is likely to produce sparks, therefore, make sure no flammable gas or
fluid is in the vicinity.
Crankshaft position sensor resis-
tance
228–342 
Pocket tester 90890-03112
Analog pocket tester YU-03112-C
• Positive tester probe 
Gray “1”
• Negative tester probe 
Black “2”
Lean angle sensor output voltageOperating angle45 °
Output voltage up to operating
angle 3.7–4.4 V
Output voltage over operating an-
gle 0.4–1.4 V
12
Gy B
Pocket tester90890-03112
Analog pocket tester YU-03112-C
Test harness– lean angle sensor
(6P) 90890-03209
Test harness– lean angle sensor
(6P) YU-03209
• Positive tester probe  Yellow/Green “1”
• Negative tester probe 
Black/Blue “2”
2
1
Ã45
Ã
45

ELECTRICAL COMPONENTS
9-78
b. Measure the resistance of the resister.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GC1399CHECKING THE RADIATOR FAN MOTOR
1. Check:• Radiator fan motor
Faulty/rough movement  Replace.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Disconnect the radiator fan motor coupler
from the wire harness.
b. Connect the battery (DC 12 V) as shown.
c. Measure the radiator fan motor movement.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GC1400CHECKING THE COOLANT TEMPERATURE
SENSOR
1. Remove: • Coolant temperature sensor
EWA
WARNING
• Handle the coolant temperature sensor with special care.
• Never subject the coolant temperature sensor to strong shocks. If the coolant
temperature sensor is dropped, replace it. 2. Check:
• Coolant temperature sensor resistanceOut of specification  Replace.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect the pocket tester (  1k/100) to
the coolant temperature sensor.
b. Immerse the coolant temperature sensor in a container filled with coolant.
TIP
Make sure the coolant temperature sensor ter-
minals do not get wet.
c. Place a thermometer in the coolant.
d. Slowly heat the coolant, and then let it cool to the specified temperature indicated in the
table.
e. Check the coolant temperature sensor for continuity at the temperatures indicated in
the table.
• Positive tester probe 
Black “1”
• Negative tester probe 
Black “2”
• Positive battery terminal 
Blue “1”
• Negative battery terminal 
Black “2”
1
2
12
12V
LB
Coolant temperature sensor re-
sistance 2512–2777  at 20 °C (2512–
2777  at 68 °F)
210–220  at 100 °C (210–220 
at 212 °F)
Pocket tester 90890-03112
Analog pocket tester YU-03112-C
• Positive tester probe  Green/White “1”
• Negative tester probe 
Black/Blue “2”
12
G/W B/L
B/LG/W

ELECTRICAL COMPONENTS
9-79
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GC1401CHECKING THE THROTTLE POSITION
SENSOR
1. Remove:• Throttle position sensor(from the throttle body)
EWA
WARNING
• Handle the throttle position sensor with special care.
• Never subject the throttle position sensor to strong shocks. If the throttle position
sensor is dropped, replace it.
2. Check: • Throttle position sensor maximum resis-
tance
Out of specification  Replace.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect the pocket tester (  1k) to the
throttle position sensor. b. Check the throttle position sensor maximum
resistance.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
3. Install:
• Throttle position sensor
TIP
When mounting the throttle position sensor, ad-
just its angle properly. Refer to “ADJUSTING
THE THROTTLE POSITION SENSOR” on
page 8-11.
EAS2GC1402CHECKING THE THROTTLE POSITION
SENSOR INPUT VOLTAGE
1. Check:• Throttle position sensor input voltageOut of specification  Replace the ECU.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect the test harness S-pressure sensor
(3P) to the throttle position sensor coupler
and the wire harness.
b. Connect the pocket tester (20 VDC) to the
test harness S-pressure sensor (3P).
Resistance
6.30 k
Pocket tester 90890-03112
Analog pocket tester YU-03112-C
• Positive tester probe Blue “1”
• Negative tester probe 
Black/Blue “2”
Throttle position sensor input
voltage4–6 V
Pocket tester 90890-03112
Analog pocket tester YU-03112-C
Test harness S– pressure sensor
(3P) 90890-03207
Test harness S– pressure sensor
(3P) YU-03207
21

ELECTRICAL COMPONENTS
9-80
c. Start the engine.
d. Measure the throttle position sensor input voltage.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GC1403CHECKING THE INTAKE AIR PRESSURE
SENSOR
1. Check:
• Intake air pressure sensor output voltageOut of specification  Replace.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect the pocket tester (20 VDC) to the
intake air pressure sensor coupler (wire har-
ness side). b. Start the engine.
c. Measure the intake air pressure sensor out-
put voltage.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GC1404CHECKING THE INTAKE AIR TEMPERA-
TURE SENSOR
1. Remove:• Intake air temperature sensor(from the air filter case)
EWA
WARNING
• Handle the intake air temperature sensor with special care.
• Never subject the intake air temperature sensor to strong shocks. If the intake air
temperature sensor is dropped, replace it.
2. Check: • Intake air temperature sensor resistanceOut of specification  Replace.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect the pocket tester (  1k/100) to
the intake air temperature sensor terminal.
• Positive tester probe 
Blue “1”
• Negative tester probe 
Black/Blue “2”
Intake air pressure sensor output
voltage3.61–3.67 V at 101.3 kPa (3.61–
3.67 V at 1.01kgf/cm
2, 3.61–3.67
V at 14.7 psi)
Pocket tester 90890-03112
Analog pocket tester YU-03112-C
• Positive tester probe 
Pink “1”
• Negative tester probe 
Black/Blue “2”
21
Intake air temperature sensor re-
sistance 290–390  at 80 °C (290–390 
at 176 °F)
Pocket tester 90890-03112
Analog pocket tester YU-03112-C
• Positive tester probe  Brown/White “1”
• Negative tester probe 
Black/Blue “2”
12

EAS2GC1427
WIRING DIAGRAM
WR450F/WR450FG 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
51. Engine ground sub-lead
EAS2GC1428
COLOR 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