2016 YAMAHA WR 450F Owners Manual

FUEL INJECTION SYSTEM
9-55
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay.
Fault code No. Er-4
Item Registered data cannot be received from the Yamaha diagnos-
tic tool.
Fail-safe system Able to start engine
Able 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 Yamaha diag- nostic tool 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.
light green–light green 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 Yamaha diagnostic tool mal- function. Replace the Yamaha diag-
nostic tool. 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.

FUEL PUMP SYSTEM
9-56
EAS2GC1379
FUEL PUMP SYSTEM
EAS2GC1380CIRCUIT DIAGRAM
ONOFF
ONOFF
BBB
BBB
RRR
RRR/L
Br Br BrBr Br
(Gy)
(Gy)B/LGyWW W BGy
BR
WW W
BR
R,R/Y
G
R
Y/B
R,R/W
Br
RL/R
(B)R/YR/WBr/WL/G
Br/W,BrL/W
(B)
(B) Br BrL/Y
Y/R
G/YBrBB
BrBrL/YY/W
(B) (B)B BGG/Y
RR/L
RLg
W/B
(B)
BGyBr RW/BB/LLYP
G/WB/Y
R/BLgG/YW
Br/W
OL/RY/BB/OL/BSbY/R
L/Y P/L
Y/G
(Gy)R/L R/BR/LB/Y
R/WR/L
R/W,BrP/L
R/L R/L
(B)
(B) (B)
(L)
(L) (B)
BR/LLBR/L R/L R/L R/L R/L B/L B/L B/L B/L B/L B/L B/LLLLLBBBB
Br Br Br Br
B/LBr/W
B/LG/WLYB/L
B/LPLB/LY/GL
(B)
(B)B/OBBBSbW/B
Sb
SbG/B
L/G,L/WL/BBrG/BG/BB
BB
(B)
(B)L/BBBB
Br Br
Br BrBr
BB
LY
(B)
(B)
(B)
(B)
(B)
GB
ChDg YB
BRW
BrRBW
B/WRW
Ch DgYBBrR/WBW
R
O
OR/L
BB
B
B
BBBBBB
RRRRRR/L
BrBrBrBrBr
Br
Br
BrBrBrBrR/LR/LR/LR/LR/L
B
LLLP
PL
Y
Y
RR
Br
R/LR/L
R/L
P/L
P/L
R/L
R/L
R/LR/B
R/B
L/RL/Y
L/Y
Y/R
Y/R
G/Y
G/YG/Y
G/Y
B/Y
B/Y
R/LB/LB/L
B/LB/LB/LY/G
Y/GB/L
B/OL/BY/BW/B
W/B
G/B
L/B
W/BW/B
L/BL/BL/GL/W
L/W
L/R
Br/W
Br/W
R/W
R/W
R/Y
R/Y
G/BG/B
G/B
B/O
B/LB/LB/LB/LB/LB/LB/L
G/W
G/W
Br/W
Br/W
R/WR/WBr
O
O
RGy
LLLLBBBB
B
B
B
B
BB
B
B
RRWW
Y
Y
Dg
Dg
Ch
Ch
RW
BrBrBrBr
Br
B
W
Sb
SbSb
SbBr
Br
B
Br
Lg
Lg
R/L
R
R
RR
Gy
BB
WWWWWW
R
RRGGBB
B
Y/B
BB
Br
Br
Br
L/G
B/L
B/WB/W
OR
OR
RBBB
B
BBBBB

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.

FUEL PUMP SYSTEM
9-59
EAS2GC1382

ELECTRICAL COMPONENTS
9-60
ELECTRICAL COMPONENTS
EAS2GC1383
910
11
1
3
2
4
5
6
7
8

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
9-62
12
1110
2
3
16
7
4
5
8
9