2004 YAMAHA YZF-R1S fuel pump

8-35
SIGNALING SYSTEMELEC
1Main switch
4Fuse (main)
6Battery
10Starting circuit cut-off relay
11Neutral switch
13Fuel pump
14E.C.U.
27Speed sensor
38Fuel level warning light
39Oil level warning light
40Neutral indicator light
41Tachometer
42Shift timing indicator light
43Multi function meter
45Coolant temperature indicator light
47Turn signal indicator light (left)
48Turn signal indicator light (light)
55Turn signal relay
58Horn switch
60Turn signal switch
61Horn
62Front turn signal / position light (left)
63Front turn signal / position light (right)
64Rear turn signal light (left)
65Rear turn signal light (right)
73Fuse (ignition)
74Fuse (signal)
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8-41
SIGNALING SYSTEMELEC
3. Voltage

Connect the pocket tester (DC 20 V) to the
meter assembly coupler (wire harness side)
as shown.
Positive tester probe
black / red
Negative tester probe
black / white
1
2

Turn the main switch to “ON”.

Measure the voltage (DC 12V) of black /
red and black / white at the meter as-
sembly coupler.

Is the voltage within specification?
12
YESNO
The wiring circuit
from the main switch
to the meter assem-
bly is faulty and must
be repaired.
This circuit is OK.
EAS00803
6. The fuel level warning light fails to come on.
1. Fuel sender

Drain the fuel from the fuel tank and remove
the fuel pump from the fuel tank.

Disconnect the fuel sender coupler from the
wire harness.

Connect the pocket tester (Ω
10) to the
fuel sender terminals as shown.
Positive tester probe
green / white
Negative tester probe
black
1
2
Fuel sender resistance
Full position of the float
20  26 Ω at 20C (68F)
Empty position of the float
134  140 Ω at 20C (68F)

Is the fuel sender OK? Measure the resistances when the float arm
is in contact with the full position and empty
position of the stopper.
NOTE:
Measure the fuel sender resistances.
YESNO
Replace the fuel
pump.
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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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8-53
SELF-DIAGNOSISELEC
SELF-DIAGNOSIS
The YZF-R1(S) features a self-diagnosing system for the following circuit(-s):

Fuel pump thermistor

Oil level switch
If any of these circuits are defective, their respective condition codes will be displayed on the warning
light when the main switch is turned “ON” (irrespective of whether the engine is running or not).
Circuit
Defect(-s)System responseCondition code
Fuel pump
thermistor
Open-circuit

Short-circuit
The fuel level warning light indi-
cate the condition code.Refer to *1
Oil level switch
Open-circuit

Short-circuit
The oil level warning light indicate
the condition code.Refer to *2
*1Condition code
Fuel level warning light
*
2Condition code
Oil level warning light
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