2016 YAMAHA WR 450F battery

COOLING SYSTEM
9-25
1. Joint connector
2. Joint connector
3. Joint connector
7. Main relay
9. Battery
10.Frame ground
11.Starter relay
12.Main fuse
22.ECU (engine control unit)
27.Radiator fan motor relay
28.Radiator fan motor fuse
29.Radiator fan motor
30.Joint connector
32.Coolant temperature sensor
48.Frame ground
50.Negative battery lead

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.

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
9-33
2. Connect the FI diagnostic tool sub-lead.
ECA
NOTICE
In order to avoid short circuit, insulate the battery connection terminals of the FI diagnostic
tool sub-lead.
TIP
For information on how to connect and use the Yamaha diagnostic tool, refer to “YAMAHA DIGNO-
STIC TOOL OPERATION MANUAL”.FI diagnostic tool sub–lead
90890-03212
FI diagnostic tool sub–lead YU-03212
1. Vehicle
2. Coupler for connecting optional part
3. FI diagnostic tool sub-lead
4. Sub-harness (included with the Yamaha di- agnostic tool)
5. Vehicle communication cable (included with the Yamaha diagnostic tool)
6. Yamaha diagnostic tool
1
2
3
2
456

FUEL INJECTION SYSTEM
9-49
Fault code No.43
Item Fuel system voltage: incorrect voltage supplied to the fuel in-
jector and fuel pump.
Fail-safe system Able to start engine
Able to drive vehicle
Diagnostic code No. 09
Diagnostic tool display Fuel system voltage
Approximately 12.0 (V)
Procedure Disconnect the main relay, and push the start switch or push down
the kickstarter lever.
Item Probable cause of malfunc-
tion and check Maintenance jobConfirmation of service
completion
1 Connection of main relay 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. 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.
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. 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 3.
3 Wire harness continuity. Open or short circuit  Re-
place the wire harness.
Between battery terminal and
ECU coupler.
red-red
red-red/white
Between main relay coupler
and ECU coupler.
brown-brown
blue/red-blue/red 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 Defective main relay. No operating sound  Re-
place the main relay. 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 Defective main relay. Execute the diagnostic mode. (Code No. 09)
Fuel system voltage is below
3 V  Replace the main re-
lay. 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 Malfunction in ECU. Replace the ECU.

FUEL INJECTION SYSTEM
9-51
Fault code No.46
Item Charging voltage is abnormal.
Fail-safe system Able/Unable to start engine
Able/Unable to drive vehicle
Diagnostic code No. —
Diagnostic tool display —
Procedure —
Item Probable cause of malfunc-
tion and check Maintenance jobConfirmation of service
completion
1 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. 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.
2 Wire harness continuity. Open or short circuit Re-
place the wire harness.
Between rectifier/regulator
coupler and ECU coupler.
red–red
Between battery terminal and
ECU coupler.
red–red 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 3.
3 Defective AC magneto. Check the AC magneto. Refer to “CHARGING SYS-
TEM” on page 9-12.
Defective AC magneto  Re-
place. 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 Malfunction in ECU. Replace the ECU.

FUEL PUMP SYSTEM
9-57
1. Joint connector
2. Joint connector
9. Battery
10.Frame ground
11.Starter relay
12.Main fuse
22.ECU (engine control unit)
26.Fuel pump
30.Joint connector
36.Engine stop switch
48.Frame ground
50.Negative battery lead

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.