2016 YAMAHA WR 450F fuel pressure

FUEL INJECTION SYSTEM
9-29
1. Joint connector
2. Joint connector
3. Joint connector
4. AC magneto
7. Main relay
9. Battery
10.Frame ground
11.Starter relay
12.Main fuse
15.Indicator light
16.Engine trouble warning light
22.ECU (engine control unit)
25.Injector
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
42.Joint connector
48.Frame ground
50.Negative battery lead

FUEL INJECTION SYSTEM
9-37
TIP
• If fault code Nos. 13 and 14 are both displayed, perform the checks and maintenance jobs for fault
code No. 13 first.
• Before troubleshooting, disconnect the star ter motor lead from the starter relay.
Fault code No. 13
Item Intake air pressure sensor: open or short circuit detected.
Fail-safe system Able to start engine
Able to drive vehicle
Diagnostic code No. 03
Diagnostic tool display Displays the intake air pressure.
Procedure Operate the throttle while pushing the start switch.(If the display
value changes, the performance is OK.)
Item Probable cause of malfunc-
tion and check Maintenance jobConfirmation of service
completion
1 Connection of intake air pres- sure 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 intake air pressure
sensor coupler and ECU cou-
pler.
black/blue–black/blue
pink–pink
blue–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 Installed condition of intake air pressure sensor.
Check for looseness or
pinching. Improperly installed sensor

Reinstall or replace the
sensor. Push the start switch.
Fault code number is not dis-
played
 Service is finished.
Fault code number is dis-
played  Go to item 5.

FUEL INJECTION SYSTEM
9-38
TIP
• If fault code Nos. 13 and 14 are both displayed, perform the checks and maintenance jobs for fault
code No. 13 first.
• Before troubleshooting, disconnect the star ter motor lead from the starter relay.
5 Defective intake air pressure
sensor. Execute the diagnostic mode.
(Code No. 03)
When engine is stopped:
Atmospheric pressure at the
current altitude and weather
conditions is indicated.
At sea level: Approx. 101 kPa
1000 m above sea level: Ap-
prox. 90 kPa
2000 m above sea level: Ap-
prox. 80 kPa
3000 m above sea level: Ap-
prox. 70 kPa
When engine is cranking:
Make sure that the indication
value changes.
The value does not change
when engine is cranking.

Check the intake air pressure
sensor.
Replace if defective.
Refer to “CHECKING THE
INTAKE AIR PRESSURE
SENSOR” on page 9-80. Push the start switch.
Fault code number is not dis-
played
 Service is finished.
Fault code number is dis-
played  Go to item 6.
6 Malfunction in ECU. Replace the ECU.
Fault code No. 14
Item Intake air pressure sensor: hose system malfunction (clogged
or detached hose).
Fail-safe system Able to start engine
Able to drive vehicle
Diagnostic code No. 03
Diagnostic tool display Displays the intake air pressure.
Procedure Operate the throttle while pushing the start switch.(If the display
value changes, the performance is OK.)
Item Probable cause of malfunc-
tion and check Maintenance jobConfirmation of service
completion
1 The intake air pressure sen- sor hose is damaged, discon-
nected, clogged, twisted or
bent. Repair or replace the sensor
hose.
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 2.
Fault code No. 13
Item Intake air pressure sensor: open or short circuit detected.

FUEL INJECTION SYSTEM
9-39
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay.
2 Defective intake air pressure
sensor. Execute the diagnostic mode.
(Code No. 03)
When engine is stopped:
Atmospheric pressure at the
current altitude and weather
conditions is indicated.
At sea level: Approx. 101 kPa
1000 m above sea level: Ap-
prox. 90 kPa
2000 m above sea level: Ap-
prox. 80 kPa
3000 m above sea level: Ap-
prox. 70 kPa
When engine is cranking:
Make sure that the indication
value changes.
The value does not change
when engine is cranking.

Check the intake air pressure
sensor.
Replace if defective.
Refer to “CHECKING THE
INTAKE AIR PRESSURE
SENSOR” on page 9-80.
Fault code No. 15
Item Throttle position sensor: open or short circuit detected.
Fail-safe system Able to start engine
Able to drive vehicle
Diagnostic code No. 01
Diagnostic tool display Throttle position sensor signal
• 11–14 (fully closed position)
• 109–116 (fully open position)
Procedure • Check with throttle valve fully closed.
• Check with throttle valve fully open.
Item Probable cause of malfunc-
tion and check Maintenance jobConfirmation of service
completion
1 Connection of throttle posi- tion 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.
Fault code No.
14
Item Intake air pressure sensor: hose system malfunction (clogged
or detached hose).

FUEL PUMP SYSTEM
9-58
EAS2GC1381TROUBLESHOOTING
The fuel pump fails to operate.
TIP
Before troubleshooting, remove the following part(s):
1. Seat
2. Side cover (left/right)
3. Air scoop (left/right)
4. Fuel tank1. Check the fuse. Refer to “CHECKING THE FUSES”
on page 9-68. NG

Replace the fuse(s).
OK 
2. Check the battery. Refer to “CHECKING AND
CHARGING THE BATTERY” on
page 9-69. NG

• Clean the battery terminals.
• Recharge or replace the battery.
OK 
3. Check the engine stop switch. Refer to “CHECKING THE
SWITCHES” on page 9-64. NG

Replace the engine stop switch.
OK 
4. Check fuel pressure. Refer to “CHECKING THE FUEL
PRESSURE” on page 8-5. NG

Replace the fuel pump.
OK 
5. Check the fuel pump system wire harness connections.
Refer to “CIRCUIT DIAGRAM” on
page 9-56. NG

Properly connect or repair the fuel pump
system’s wiring.
OK 
Replace the ECU.

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