2016 YAMAHA WR 450F fuel

ELECTRICAL COMPONENTS
9-61
1. Rectifier/regulator
2. Clutch switch
3. Ignition coil
4. ECU (engine control unit)
5. Fuel sender
6. Fuel pump
7. Battery
8. Resistor
9. Neutral switch
10.Radiator fan motor
11.Injector

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
9-81
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EAS2GC1405CHECKING THE FUEL INJECTOR
1. Remove:• Fuel injector
Refer to “THROTTLE BODY” on page 8-7.
2. Check: • Fuel injector resistance
Out of specification  Replace.
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a. Disconnect the fuel injector coupler from the
fuel injector.
b. Connect the pocket tester (  10) to the
fuel injector coupler.
c. Measure the fuel injector resistance.
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Resistance 12 
Pocket tester 90890-03112
Analog pocket tester YU-03112-C
• Positive tester probe 
Injector terminal “1”
• Negative tester probe 
Injector terminal “2”
12
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

TROUBLESHOOTING
10-2
Electrical system
1. Battery• Discharged battery
• Faulty battery
2. Spark plug • Incorrect spark plug gap
• Incorrect spark plug heat range
• Fouled spark plug
• Worn or damaged electrode
• Worn or damaged insulator
• Faulty spark plug cap
3. Ignition coil
• Broken or shorted primary or secondary coil
• Cracked or broken ignition coil
4. Ignition system • Faulty ECU
• Faulty crankshaft position sensor
• Broken generator rotor woodruff key
EAS2GC1410POOR MEDIUM-AND-HIGH-SPEED PER-
FORMANCE
Refer to “STARTING FAILURES” on page 10-
1.
Engine
1. Air filter
• Clogged air filter element
Fuel system
1. Fuel pump • Faulty fuel pump
2. Throttle body
• Defective throttle body
3. ECU • Faulty ECU
EAS2GC1411SHIFTING IS DIFFICULT
Refer to “CLUTCH” on page 6-41.
EAS2GC1412SHIFT PEDAL DOES NOT MOVE
Engine
1. Shift shaft
• Bent shift shaft
2. Shift drum and shift forks • Foreign object in a shift drum groove
• Seized shift fork
• Bent shift fork guide bar
3. Transmission
• Seized transmission gear
• Foreign object between transmission gears
• Improperly assembled transmission
EAS2GC1413
JUMPS OUT OF GEAR
Engine
1. Shift shaft• Incorrect shift pedal position
• Improperly returned stopper lever
2. Shift forks
• Worn shift fork
3. Shift drum • Incorrect axial play
• Worn shift drum groove
4. Transmission • Worn gear dog
EAS2GC1414CLUTCH SLIPS
Engine
1. Clutch• Improperly assembled clutch
• Loose or fatigued clutch spring
• Worn friction plate
• Worn clutch plate
2. Engine oil
• Incorrect oil level
• Incorrect oil viscosity (low)
• Deteriorated oil
EAS2GC1415CLUTCH DRAGS
Engine
1. Clutch• Unevenly tensioned clutch springs
• Warped pressure plate
• Bent clutch plate
• Swollen friction plate
• Bent clutch push rod
• Damaged clutch boss
• Burnt primary driven gear bushing
2. Engine oil • Incorrect oil level
• Incorrect oil viscosity (high)
• Deteriorated oil
EAS2GC1416OVERHEATING
Engine
1. Cylinder head and piston• Heavy carbon buildup
• Clogged coolant passages
2. Engine oil
• Incorrect oil level
• Incorrect oil viscosity
• Inferior oil quality

TROUBLESHOOTING
10-3
Cooling system
1. Coolant• Low coolant level
2. Radiator • Damaged or leaking radiator
• Faulty radiator cap
• Bent or damaged radiator fin
3. Water pump • Damaged or faulty water pump
• Damaged hose
• Improperly connected hose
• Damaged pipe
• Improperly connected pipe
Fuel system
1. Throttle body • Damaged or loose throttle body joint
2. Air filter • Clogged air filter element
Chassis
1. Brake(s) • Dragging brake
Electrical system
1. Spark plug • Incorrect spark plug gap
• Incorrect spark plug heat range
2. Ignition system • Faulty ECU
• Faulty coolant temperature sensor
EAS2GC1417OVERCOOLING
Cooling system
1. Coolant temperature sensor• Faulty coolant temperature sensor
EAS2GC1418POOR BRAKING PERFORMANCE
Chassis
1. Brake(s)• Worn brake pad
• Worn brake disc
• Air in hydraulic brake system
• Leaking brake fluid
• Defective master cylinder kit
• Faulty brake caliper kit
• Faulty brake caliper seal
• Loose union bolt
• Damaged brake hose
• Oil or grease on the brake disc
• Oil or grease on the brake pad
• Incorrect brake fluid level
EAS2GC1419FRONT FORK OIL LEAKING
Chassis
1. Front fork• Bent, damaged, or rusty inner tube
• Cracked or damaged outer tube
• Improperly installed oil seal
• Damaged oil seal lip
• Incorrect oil level (high)
• Loose damper rod assembly bolt
• Damaged damper rod assembly bolt copper
washer
• Cracked or damaged cap bolt O-ring
EAS2GC1420FAULTY FRONT FORK LEGS
Chassis
1. Front fork • Bent or damaged inner tube
• Bent or damaged outer tube
• Broken fork spring
• Bent or damaged damper rod
• Incorrect oil viscosity
• Incorrect oil level
EAS2GC1421UNSTABLE HANDLING
Chassis
1. Handlebar• Bent or improperly installed handlebar
2. Steering head components • Improperly installed upper bracket
• Improperly installed lower bracket(improperly tightened ring nut)
• Bent steering stem
• Damaged ball bearing or bearing race
3. Front fork leg (s) • Uneven oil levels (both front fork legs)
• Unevenly tensioned fork spring (both front fork legs)
• Broken fork spring
• Bent or damaged inner tube
• Bent or damaged outer tube
4. Swingarm • Worn bearing or bushing
• Bent or damaged swingarm
5. Rear shock absorber assembly (-ies) • Faulty rear shock absorber spring
• Leaking oil or gas
6. Tire (s) • Uneven tire pressures (front and rear)
• Incorrect tire pressure
• Uneven tire wear

LIST OF SELF-DIAGNOSTIC AND FAIL-SAFE ACTIONS
10-5
EAS2GC1425
LIST OF SELF-DIAGNOSTIC AND FAIL-SAFE ACTIONS
LIST OF DIAGNOSTIC CODES
COMMUNICATION ERROR WITH YAMAHA DIAGNOSTIC TOOLFault
code Item Page
12 Crankshaft position sensor: no normal signals are received from the crankshaft position sensor. 9-35
13 Intake air pressure sensor: open or short circuit detected. 9-37
14 Intake air pressure sensor: hose system malfunction (clogged or de- tached hose) 9-38
15 Throttle position sensor: open or short circuit detected. 9-39
16 Throttle position sensor: stuck throttle position sensor is detected. 9-41
21 Coolant temperature sensor: open or short circuit detected. 9-42
22 Intake air temperature sensor: open or short circuit detected. 9-43
30 Latch up detected. 9-44
33 Ignition coil: open or short circuit detected in the primary lead of the ignition coil. 9-45
39 Injector: open or short circuit detected. 9-47
41 Lean angle sensor: open or short circuit detected. 9-48
43 Fuel system voltage: incorrect voltage supplied to the fuel injector and fuel pump. 9-49
44 EEPROM fault code number: an error is detected while reading or writing on EEPROM. 9-50
46 Charging voltage is abnormal. 9-51
50 Faulty ECU memory. (When this malfunction is detected in the ECU, the fault code number might not appear on the meter.) 9-52
Fault code Item Page
Waiting
for con-
nection No communication signal is received from the ECU.
9-52
Er-2 Signals from the ECU cannot be re ceived within the specified period
of time. 9-53
Er-3 Data from the ECU cannot be received correctly. 9-54
Er-4 Registered data cannot be received from the Yamaha diagnostic tool. 9-55

LIST OF SELF-DIAGNOSTIC AND FAIL-SAFE ACTIONS
10-6
SENSOR OPERATION TABLEDiag-
nostic code No. Item Display Procedure
01 Throttle position sensor sig- nal
• Fully closed position
• Fully opened position • 11–14
• 109–116 • Check with throttle valve
fully closed.
• Check with throttle valve fully open.
03 Intake air pressure Displays the intake air pres- sure.Operate the throttle while
pushing the start switch. (If
the display value changes,
the performance is OK.)
05 Intake air temperature Displays the intake air tem- perature.Compare the actually mea-
sured intake air tempera-
ture with the Yamaha
diagnostic tool display val-
ue.
06 Coolant temperature When engine is cold: Dis- plays temperature closer to
air temperature.
When engine is hot: Displays
current coolant temperature.Compare the actually mea-
sured coolant temperature
with the Yamaha diagnostic
tool display value.
07 Vehicle speed pulses Vehicle speed pulse 0–999Check that the number in-
creases when the front
wheel is rotated. The num-
ber is cumulative and does
not reset each time the
wheel is stopped.
08 Lean angle sensor • Upright
• Overturned Displays the output voltage.
• 0.4–1.4
• 3.7–4.4 Remove the lean angle
sensor, and incline it more
than 45 degrees.
09 Monitor voltage Displays the fuel system volt- age.
• Approximately 12.0 (V)—
21 Neutral switch • Gear in neutral
• Gear not in neutral •ON
•OFF Operate the shift pedal.
60 EEPROM fault code display • No fault
• CO adjustment value
• Setting tool adjustment values 0–8 for fuel injec-
tion amount or ignition tim-
ing •00
•01
•07
—
61 Malfunction history ( ) code No. display *1
• There is no history.
• There is some history. •00
• Other: Displays the fault
code of ( ). —