sensor YAMAHA WR 450F 2016 Workshop Manual

FUEL INJECTION SYSTEM
9-46
3 Connection of sub wire har-ness coupler.Check the lock-
ing condition of the
coupler.Disconnect the cou-
pler and check the pins (bent
or broken terminals and lock-
ing condition of the pins). Improperly connected

Connect the coupler secure-
lyor repair/replace the sub
wire harness. Start the engine and let it idle
for approximately 5 seconds.
Fault code number is not dis-
played
 Service is finished.
Fault code number is dis-
played  Go to item 4.
4 Wire harness continuity. Open or short circuit  Re-
place the wire harness.
Between ignition coil coupler
and ECU coupler.
orange–orange Start the engine and let it idle
for approximately 5 seconds.
Fault code number is not dis-
played
 Service is finished.
Fault code number is dis-
played  Go to item 5.
5 Installed condition of ignition coil.
Check for looseness or
pinching. Improperly installed sensor

Reinstall or replace the
sensor. Start the engine and let it idle
for approximately 5 seconds.
Fault code number is not dis-
played
 Service is finished.
Fault code number is dis-
played  Go to item 6.
6 Defective ignition coil. (test the primary coils for continu-
ity) Check the ignition coil.
Replace if defective.
Refer to “CHECKING THE
IGNITION COIL” on page 9-
74. Start the engine and let it idle
for approximately 5 seconds.
Fault code number is not dis-
played
 Service is finished.
Fault code number is dis-
played  Go to item 7.
7 Malfunction in ECU. Execute the diagnostic mode (diagnostic code No. 30).
No spark  Replace the
ECU.
Fault code No. 33
Item
Ignition coil: open or short circuit detected in the primary lead
of the ignition coil.

FUEL INJECTION SYSTEM
9-48
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay.
Fault code No. 41
Item Lean angle sensor: open or short circuit detected.
Fail-safe system Unable to start engine
Able to drive vehicle
Diagnostic code No. 08
Diagnostic tool display Lean angle sensor output voltage
• 0.4–1.4 (upright)
• 3.7–4.4 (overturned)
Procedure Remove the lean angle sensor and incline it more than 45 degrees.
Item Probable cause of malfunc-
tion and check Maintenance jobConfirmation of service
completion
1 Connection of lean angle sensor 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.
Between lean angle sensor
coupler and ECU coupler.
blue–blue
yellow/green–yellow/green
black/blue–black/blue Push the start switch.
Fault code number is not dis-
played
 Service is finished.
Fault code number is dis-
played  Go to item 4.
4 Defective lean angle sensor. Execute the diagnostic mode. (Code No. 08)
Replace if defective.
Refer to “CHECKING THE
LEAN ANGLE SENSOR” on
page 9-75.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.

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

ELECTRICAL COMPONENTS
9-74
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a. Connect the pocket tester ( 1k) to the
spark plug cap.
b. Measure the spark plug cap resistance.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GC1391CHECKING THE IGNITION COIL
1. Disconnect: • Ignition coil terminal(from the sub wire harness)
• Spark plug cap (from the ignition coil)
2. Check:
• Primary coil resistanceOut of specification  Replace.
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a. Connect the pocket tester (  1) to the igni-
tion coil. b. Measure the primary coil resistance.
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3. Check:
• Secondary coil resistanceOut of specification  Replace.
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a. Connect the pocket tester (  1k) to the ig-
nition coil.
b. Measure the secondary coil resistance.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GC1392CHECKING THE CRANKSHAFT POSITION
SENSOR
1. Disconnect: • Crankshaft position sensor coupler(from the wire harness)
2. Check:
• Crankshaft position sensor resistanceOut of specification  Replace.
Pocket tester
90890-03112
Analog pocket tester YU-03112-C
Primary coil resistance 2.16–2.64 
Pocket tester 90890-03112
Analog pocket tester YU-03112-C
• Positive tester probe 
Ignition coil terminal 1 “1”
• Negative tester probe 
Ignition coil terminal 2 “2”
Secondary coil resistance 8.64–12.96 k 
Pocket tester 90890-03112
Analog pocket tester YU-03112-C
• Positive tester probe  Ignition coil terminal 1 “1”
• Negative tester probe 
Spark plug lead “2”

ELECTRICAL COMPONENTS
9-75
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a. Connect the pocket tester ( 100) to the
crankshaft position sensor coupler.
b. Measure the crankshaft position sensor re- sistance.
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EAS2GC1393CHECKING THE LEAN ANGLE SENSOR
1. Remove:• Lean angle sensor
(from the bracket)
2. Check: • Lean angle sensor output voltage
Out of specification  Replace.
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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.
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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.
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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
9-77
EAS2GC1396CHECKING THE SPEED SENSOR
1. Check:• Speed sensor output voltageOut of specification  Replace.
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a. Connect the test harness-speed sensor (3P)
to the speed sensor coupler and wire har-
ness.
b. Connect the pocket tester (DC20V) to the test harness-speed sensor (3P).
c. Push the start switch.
d. Elevate the front wheel and slowly turn it.
e. Measure the voltage (DC 5 V) of white and black/white. With the front wheel slowly ro-
tating, voltage alternates between 0 V and 5
V.
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EAS2GC1397CHECKING THE FUEL SENDER
1. Drain the gasoline.
2. Disconnect:• Fuel sender coupler
(from the fuel sender)
3. Remove:
• Fuel sender(from the fuel tank) 4. Check:
• Fuel sender resistanceOut of specification  Replace the fuel
sender.
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a. Connect the pocket tester (  1k) to the
fuel sender as shown.
b. Measure the resistance of the fuel sender.
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EAS2GC1398CHECKING THE RESISTER
1. Disconnect: • Resister coupler(from the wire harness)
2. Check: • Resister resistanceOut of specification  Replace the resister.
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a. Connect the pocket tester (  10) to the re-
sister as shown.
Output voltage reading cycle
0.6V to 4.8V to 0.6V to 4.8V
Pocket tester 90890-03112
Analog pocket tester YU-03112-C
Test harness– speed sensor 5TJ
(3P) 90890-03228
Test harness– speed sensor 5TJ
(3P) YU-03228
• Positive tester probe  White “1”
• Negative tester probe 
Black “2”
BRW
21
Fuel sender resistance
1.35–1.90 k  at 25°C (77°F)
Pocket tester 90890-03112
Analog pocket tester YU-03112-C
• Positive tester probe  Green “1”
• Negative tester probe 
Black “2”
Resister resistance64.6–71.4 
Pocket tester 90890-03112
Analog pocket tester YU-03112-C
1
2

ELECTRICAL COMPONENTS
9-78
b. Measure the resistance of the resister.
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EAS2GC1399CHECKING THE RADIATOR FAN MOTOR
1. Check:• Radiator fan motor
Faulty/rough movement  Replace.
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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.
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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
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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.
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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.
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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

TROUBLESHOOTING
10-1
EAS2GC1406
TROUBLESHOOTING
EAS2GC1407GENERAL INFORMATION
TIP
The following guide for troubleshooting does
not cover all the possible causes of trouble. It
should be helpful, however, as a guide to basic
troubleshooting. Refer to the relative procedure
in this manual for checks, adjustments, and re-
placement of parts.
EAS2GC1408STARTING FAILURES
Engine
1. Cylinder and cylinder head• Loose spark plug
• Loose cylinder head or cylinder
• Damaged cylinder head gasket
• Damaged cylinder gasket
• Worn or damaged cylinder
• Incorrect valve clearance
• Improperly sealed valve
• Incorrect valve-to-valve-seat contact
• Incorrect valve timing
• Faulty valve spring
• Seized valve
2. Piston and piston ring(s) • Improperly installed piston ring
• Damaged, worn or fatigued piston ring
• Seized piston ring
• Seized or damaged piston
3. Air filter • Improperly installed air filter
• Clogged air filter element
4. Crankcase and crankshaft • Improperly assembled crankcase
• Seized crankshaft
Fuel system
1. Fuel tank • Empty fuel tank
• Clogged fuel tank breather hose
• Deteriorated or contaminated fuel
• Clogged or damaged fuel hose
2. Fuel pump
• Faulty fuel pump
3. Throttle body • Deteriorated or contaminated fuel
• Sucked-in air Electrical system
1. Battery
• Discharged battery
• Faulty battery
2. Fuse • Blown, damaged or incorrect fuse
• Improperly installed fuse
3. Spark plug • Incorrect spark plug gap
• Incorrect spark plug heat range
• Fouled spark plug
• Worn or damaged electrode
• Worn or damaged insulator
4. Ignition coil • Cracked or broken ignition coil body
• Broken or shorted primary or secondary coils
5. Ignition system • Faulty ECU
• Faulty crankshaft position sensor
• Broken generator rotor woodruff key
6. Switches and wiring
• Faulty ECU
• Faulty engine stop switch
• Broken or shorted wiring
• Faulty neutral switch
• Improperly grounded circuit
• Loose connections
7. Starting system • Faulty starter motor
• Faulty starter relay
• Faulty starting circuit cut-off relay
• Faulty starter clutch
EAS2GC1409INCORRECT ENGINE IDLING SPEED
Engine
1. Cylinder and cylinder head• Incorrect valve clearance
• Damaged valve train components
2. Air filter • Clogged air filter element
Fuel system
1. Throttle body • Damaged or loose throttle body joint
• Improperly synchronized throttle bodies
• Improper throttle cable free play
• Flooded throttle body