2004 YAMAHA YZF-R1SC battery

8-44
1Main switch
4Fuse (main)
6Battery
14E.C.U.
28Coolant temperature sensor
73Fuse (ignition)
76Radiator fan motor relay
77Fuse (radiator fan motor left)
78Fuse (radiator fan motor right)
79Radiator fan motor 2
80Radiator fan motor 1
COOLING SYSTEMELEC
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8-45
YESNO 2. Battery

Check the condition of the battery.
Refer to “CHECKING AND CHARGING
THE BATTERY” in chapter 3.
Minimum open-circuit voltage
12.8 V or more at 20C (68F)

Is the battery OK?

Clean the battery
terminals.

Recharge or re-
place the battery.
EAS00739
EAS00749
3. Main switch

Check the main switch for continuity.
Refer to “CHECKING THE SWITCHES”.

Is the main switch OK?
YESNO
Replace the main
switch.
COOLING SYSTEMELEC
NOTE:
YESNO
1. Main, ignition and radiator fan motor fuses

Check the main, ignition and radiator fan
motor fuses for continuity.
Refer to “CHECKING THE FUSES” in chap-
ter 3.

Are the main, ignition and radiator fan motor
fuses OK?
Replace the fuse(s).
EAS00808
TROUBLESHOOTING

The radiator fan motor fails to turn.

The coolant temperature indicator light
fails to light when the engine is warm.
Check:
1. main, ignition, and radiator fan motor fuses
2. battery
3. main switch
4. radiator fan motor
5. radiator fan motor relay
6. coolant temperature sensor
7. wiring connections
(the entire cooling system)

Before troubleshooting, remove the following
part(s):
1. seat
2. fuel tank
3. side cowlings

Troubleshoot with the following special tool(s).
Pocket tester
90890-03112, YU-3112
EAS00738
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8-46
YESNO
4. Radiator fan motor

Disconnect the radiator fan motor coupler
from the wire harness.

Connect the battery (DC 12 V) as shown.
The radiator fan mo-
tor is faulty and must
be replaced.
Positive battery lead
blue
Negative battery lead
black1
2

Does the radiator fan motor turn?
5. Radiator fan motor relay

Disconnect the radiator fan motor relay
form the wire harness.

Connect the pocket tester (Ω
1) and bat-
tery (12 V) to the radiator fan motor terminal
as shown.

Check the radiator fan motor for continuity.
Replace the radiator
fan motor relay.
NOYES
Battery positive terminal
red / white
Battery negative terminal

green / yellow 1
2

Does the radiator fan motor relay have conti-
nuity between red and brown / green?
Tester positive probe
red
Tester negative probe
brown / green3
4
COOLING SYSTEMELEC
EAS00809
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8-48
1Main switch
4Fuse (main)
6Battery
7Fuse (fuel injection)
10Starting circuit cut-off relay
13Fuel pump
14E.C.U.
53Engine stop switch
FUEL PUMP SYSTEMELEC
EAS00814
FUEL PUMP SYSTEM
CIRCUIT DIAGRAM
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8-49
FUEL PUMP SYSTEMELEC
1Battery
2Fuse (main)
3Main switch
4Fuse (ignition)
5Engine stop switch
6ECU
7Fuse (fuel injection)
8Starting circuit cut-off relay (fuel injection
system relay)
9Fuel pump
EAS00815
FUEL PUMP SYSTEM
The ECU includes the control unit for the
fuel pump.
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8-50
FUEL PUMP SYSTEMELEC
YESNO 2. Battery

Check the condition of the battery.
Refer to “CHECKING AND CHARGING
THE BATTERY” in chapter 3.
Minimum open-circuit voltage
12.8 V or more at 20C (68F)

Is the battery OK?

Clean the battery
terminals.

Recharge or re-
place the battery.
EAS00739
EAS00749
3. Main switch

Check the main switch for continuity.
Refer to “CHECKING THE SWITCHES”.
YESNO
Replace the main
switch.
Is the main switch OK?
EAS00750
4. Engine stop switch

Check the engine stop switch for continuity.
Refer to “CHECKING THE SWITCHES”.
YESNO
Replace the right
handlebar switch.
Is the engine stop switch OK?
NOTE:
YESNO
1. Main, ignition and fuel injection system
fuses

Check the main, ignition and fuel system
fuses for continuity.
Refer to “CHECKING THE FUSES” in chap-
ter 3.
Replace the fuse(s).

Are the main, ignition and fuel injection sys-
tem fuses OK?
EAS00816
TROUBLESHOOTING
If the fuel pump fails to operate.
Check:
1. main, ignition and fuel injection fuses
2. battery
3. main switch
4. engine stop switch
5. starting circuit cut-off relay
(the fuel injection system relay)
6. fuel pump
7. wiring connections
(the entire fuel system)

Before troubleshooting, remove the following
part(s):
1. seat
2. fuel tank
3. side cowlings
Troubleshoot with the following special tool(s).
Pocket tester
90890-03112, YU-3112
EAS00738
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8-51
FUEL PUMP SYSTEMELEC
YESNO 5. Starting circuit cut-off relay (fuel injection
system relay)

Disconnect the starting circuit cut-off relay
coupler from the wire harness.

Connect the pocket tester (Ω
1) and bat-
tery (12 V) to the starting circuit cut-off relay
coupler as shown.
Replace the starting
circuit cut-off relay.
Positive battery lead
red / black
Negative battery lead
blue / yellow 1
2
Positive tester probe
red
Negative tester probe
red / blue3
4

Does the starting circuit cut-off relay have
continuity between red and red / blue?
YESNO 6. Fuel pump resistance

Disconnect the fuel pump coupler from the
wire harness.

Connect the pocket tester (Ω
1) to the fuel
pump coupler as shown.
Properly connect or
repair the fuel sys-
tem’s wiring.
1
2
Positive tester probe
red / blue
Negative tester probe
black
EAS00817
YESNO Fuel pump resistance
0.2  3.0 Ω at 20C (68F)

Is the fuel pump OK?
Replace the fuel
pump.

Measure the fuel pump resistance.
7. Wiring

Check the entire fuel pump system’s wiring.
Refer to “CIRCUIT DIAGRAM”.

Is the fuel system’s wiring properly con-
nected and without defects?
EAS00818
Replace the ECU.
EAS00759
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8-52
FUEL PUMP SYSTEMELEC
WARNING
EAS00819
CHECKING THE FUEL PUMP
Gasoline is extremely flammable and under
certain circumstances there can be a danger
of an explosion or fire. Be extremely careful
and note the following points:

Stop the engine before refueling.

Do not smoke, and keep away from open
flames, sparks, or any other source of fire.

If you do accidentally spill gasoline, wipe it
up immediately with dry rags.

If gasoline touches the engine when it is
hot, a fire may occur. Therefore, make sure
the engine is completely cool before per-
forming the following test.
1. Check:

Fuel pump operation
a. Insert the plug
1 to fuel return hose end.
b. Fill the fuel tank.
c. Put the end of the fuel hose into an open con-
tainer.
d. Connect the battery (DC 12 V) to the fuel
pump coupler as shown.
Positive battery lead
red / blue
2
Negative battery lead
black 3
e. If fuel flows out of the fuel hose, the fuel pump
is OK. If fuel does not flow, replace the fuel
pump.
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