2016 YAMAHA WR 450F radiator

COOLING SYSTEM
9-26
EAS2GC1372TROUBLESHOOTING
The radiator fan motor fails to turn.
TIP
Before troubleshooting, remove the following part(s):
1. Seat
2. Side cover (left)
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 main relay. Refer to “CHECKING THE RE-
LAYS” on page 9-72. NG

Replace the main relay.
OK 
4. Check the radiator fan motor. Refer to “CHECKING THE RADIA-
TOR FAN MOTOR” on page 9-78. NG

Replace the radiator fan motor.
OK 
5. Check the radiator fan motor relay. Refer to “CHECKING THE RE-
LAYS” on page 9-72. NG

Replace the radiator fan motor relay.
OK 
6. Check the coolant temperature sen- sor.
Refer to “CHECKING THE COOL-
ANT TEMPERATURE SENSOR”
on page 9-78. NG

Replace the coolant temperature sensor.
OK 
7. Check the entire cooling system’s wiring.
Refer to “CIRCUIT DIAGRAM” on
page 9-16. NG

Properly connect or repair the cooling sys-
tem’s wiring.
OK 
Replace the ECU.

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
9-63
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
9-68
Checking the condition of the bulb sockets
The following procedure applies to all of the
bulb sockets.
1. Check:• Bulb socket (for continuity)(with the pocket tester)
No continuity  Replace.
TIP
Check each bulb socket for continuity in the
same manner as described in the bulb section;
however, note the following.
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a. Install a good bulb into the bulb socket.
b. Connect the pocket tester probes to the re-
spective leads of the bulb socket.
c. Check the bulb socket for continuity. If any of
the readings indicate no continuity, replace
the bulb socket.
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EAS2GC1385CHECKING THE FUSES
The following procedure applies to all of the
fuses.
ECA
NOTICE
To avoid a short circuit, always turn off the
meter when checking or replacing a fuse.
1. Remove: • Side cover (left/right)
• SeatRefer to “GENERAL CHASSIS” on page 5-
1.
2. Check: • Main fuse “1”
• Radiator fan motor fuse “2”
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a. Connect the pocket tester to the fuse and check the continuity.
TIP
Set the pocket tester selector to “ 1”.
b. If the pocket tester indicates “ ”, replace the
fuse.
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3. Replace: • Fuse
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a. The meter light goes off.
b. Install a new fuse of the correct amperage rating.
c. Turn on the meter light to verify if the electri- cal circuit is operational.
d. If the fuse immediatel y blows again, check
the electrical circuit.
EWA
WARNING
Never use a fuse with an amperage rating
other than that specified. Improvising or us-
ing a fuse with the wrong amperage rating
may cause extensive damage to the electri-
cal system, cause the lighting and ignition
systems to malfunction and could possibly
cause a fire.
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Pocket tester 90890-03112
Analog pocket tester YU-03112-C
1
Pocket tester90890-03112
Analog pocket tester YU-03112-C
Fuses Amper-
age rating Q’ty
Main 15 A 1
Spare 15 A 1
Radiator fan motor 5 A 1
2

ELECTRICAL COMPONENTS
9-72
EAS2GC1387CHECKING 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 relay Starting 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 ba ttery terminal
3. Positive tester probe
4. Negative tester probe
Result
Continuity
(between “3” to “4”)
1. Positive battery terminal
2. Negative ba ttery terminal
3. Positive tester probe
4. Negative tester probe
Result
Continuity
(between “3” to “4”)
21
3
4
R/WBr/WR/YL/G
1
2 3
4
L/R BrR
R,R/W
1. Positive ba ttery terminal
2. Negative ba ttery terminal
3. Positive tester probe
4. Negative tester probe
Result
Continuity
(between “3” to “4”)
1. Positive ba ttery terminal
2. Negative ba ttery terminal
3. Positive tester probe
4. Negative tester probe
Result
Continuity
(between “3” to “4”)
1. Positive ba ttery terminal
2. Negative ba ttery terminal
3. Positive tester probe
4. Negative tester probe
1
2 3
4
G/B L/B
L/G,L/W
1
2 3
4
R,R/Y
G R
1
2 3
4
P/L R/L
R/W
Br,R/W

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.
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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

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
10-8
ACTUATOR OPERATION TABLEDiag-
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.