engine YAMAHA YZF-R1SC 2004 Service Manual

8-15
ELECTRIC STARTING SYSTEMELEC
EAS00756
STARTING CIRCUIT CUT-OFF SYSTEM
OPERATION
If the engine stop switch is set to “
” and the
main switch is set to “ON” (both switches are
closed), the starter motor can only operate if at
least one of the following conditions is met:

The transmission is in neutral (the neutral
switch is closed).

The clutch lever is pulled to the handlebar (the
clutch switch is closed) and the sidestand is up
(the sidestand switch is closed).
The starting circuit cut-off relay prevents the
starter motor from operating when neither of
these conditions has been met. In this instance,
the starting circuit cut-off relay is open so cur-
rent cannot reach the starter motor. When at
least one of the above conditions has been met
the starting circuit cut-off relay is closed and the
engine can be started by pressing the starter
switch.
WHEN THE TRANSMISSION IS IN
NEUTRAL
WHEN THE SIDESTAND IS UP AND
THE CLUTCH LEVER IS PULLED TO
THE HANDLEBAR
1Battery
2Main fuse
3Main switch
4Ignition fuse
5Engine stop switch
6Starting circuit cut-off relay
7Diode
8Clutch switch
9Sidestand switch
10Neutral switch
11Start switch
12Starter relay
13Starter motor
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8-16
YESNO
3. Starter motor

Connect the positive battery terminal and
starter motor lead with a jumper lead .
Repair or replace the
starter motor.
A wire that is used as a jumper lead
must have at least the same capacity or
more as that of the battery lead, other-
wise the jumper lead may burn.

This check is likely to produce sparks,
therefore make sure nothing flammable
is in the vicinity.

Does the starter motor turn?
WARNING
1
23
EAS00758
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
ELECTRIC STARTING SYSTEMELEC
NOTE:
YESNO
1. Main and ignition fuses

Check the main and ignition fuses for conti-
nuity.
Refer to “CHECKING THE FUSES” in chap-
ter 3.

Are the main and ignition fuses OK?
Replace the fuse(s).
EAS00757
TROUBLESHOOTING
The starter motor fails to turn.
Check:
1. main and ignition fuses
2. battery
3. starter motor
4. starting circuit cut-off relay
5. starter relay
6. main switch
7. engine stop switch
8. neutral switch
9. sidestand switch
10. clutch switch
11. start switch
12. wiring connections
(of the entire starting system)

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

Troubleshoot with the following special tool(s).
Pocket tester
90890-03112, YU-3112
EAS00738
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8-17
4. Starting circuit cut-off 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.
YESNO
Replace the starting
circuit cut-off relay.
Positive tester probe
blue / white
Negative tester probe
blue / white

Does the starting circuit cut-off relay have
continuity between blue / white and
blue / white ?
1
2
3
4
EAS00759
Positive battery terminal
red / black
Negative battery terminal

black / yellow
EAS00761
5. Starter relay

Disconnect the starter relay coupler from the
coupler.

Connect the pocket tester (Ω
1) and battery
(12 V) to the starter relay coupler as shown.
YESNO
Replace the starter
relay.
Positive battery terminal
blue / white
Negative battery terminal
red / white
Positive tester probe
red
Negative tester probe
black
1
2
3
4

Does the starter relay have continuity be-
tween red and black?
EAS00749
6. Main switch

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

Is the main switch OK?
YESNO
Replace the main
switch.
EAS00750
7. Engine stop switch

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

Is the engine stop switch OK?
YESNO
Replace the right
handlebar switch.
EAS00751
8. Neutral switch

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

Is the neutral switch OK?
YESNO
Replace the neutral
switch.
3
4
ELECTRIC STARTING SYSTEMELEC
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8-25
NOYES
3. Charging voltage

Set the engine tachometer to the ignition coil
of cylinder #1.

Connect the pocket tester (DC 20 V) to the
battery as shown.
The charging circuit
is OK. Positive tester probe

positive battery terminal
Negative tester probe

negative battery terminal

Start the engine and let it run at approxi-
mately 5,000 r / min.

Measure the charging voltage.
Charging voltage
14 V at 5,000 r / min

Is the charging voltage within specification?
EAS00775
YESNO

Clean the battery
terminals.

Recharge or re-
place the battery.
Make sure the battery is fully charged.
NOTE:
Minimum open-circuit voltage
12.8 V or more at 20C (68F)

Is the battery OK?
CHARGING SYSTEMELEC
NOTE:
YESNO
1. Main fuse

Check the main fuse for continuity.
Refer to “CHECKING THE FUSES” in chap-
ter 3.

Is the main fuse OK?
Replace the fuse.
2. Battery

Check the condition of the battery.
Refer to “CHECKING AND CHARGING
THE BATTERY” in chapter 3.
EAS00739 EAS00774
TROUBLESHOOTING
The battery is not being charged.
Check:
1. main fuse
2. battery
3. charging voltage
4. stator coil lead
5. stator coil resistance
6. wiring connections
(of the entire charging system)

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

Troubleshoot with the following special tool(s).
Pocket tester
90890-03112, YU-3112
EAS00738
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8-31
High beam indicator light (LEDs)
Positive tester probe
black / yellow
Negative tester probe

black / white
YESNO 1. Headlight bulb and socket

Check the headlight bulb and socket for con-
tinuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”.

Are the headlight bulb and socket OK?
Replace the head-
light bulb, socket or
both.
YESNO 2. Voltage

Connect the pocket tester (DC 20 V) to the
headlight and meter assembly couplers as
shown.
The wiring circuit
from the main switch
to the headlight cou-
pler is faulty and
must be repaired.
When the dimmer switch is set to “ ”
When the dimmer switch is set to “ ”
Headlight coupler (wire harness side)
Low beam
Headlight
Positive tester probe
black
Negative tester probe
black / green
1
2
Meter assembly coupler (wire harness side)

Turn the main switch to “ON”.

Start the engine.

Set the dimmer switch to “ ” or “ ”.

Measure the voltage (DC 12 V) of
black / green or black / yellow on the
headlight coupler (wire harness side).

Is the voltage within specification?
2
This circuit is OK.
A
B
Headlight
Positive tester probe
black
Negative tester probe
black / yellow
A
Headlight coupler (wire harness side)
High beam
B
6
5
3
4
4
LIGHTING SYSTEMELEC
EAS00788
CHECKING THE LIGHTING SYSTEM
1. The headlight and the high beam indicator
light fail to come on.
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8-40
SIGNALING SYSTEMELEC
YESNO
Replace the starting
circuit cut-off relay.
YESNO 4. Voltage

Connect the pocket tester (DC 20 V) to the
meter assembly coupler (wire harness side)
as shown.
The wiring circuit
from the main switch
to the meter assem-
bly coupler is faulty
and must be re-
paired. Positive tester probe
brown
Negative tester probe
ground
1

Turn the main switch to “ON”.

Measure the voltage (DC 12 V) of brown
at the meter assembly coupler (wire harness
side).

Is the voltage within specification?
This circuit is OK.

Are the tester readings correct?
YESNO 1. Oil level warning light (LEDs)

Check the oil level warning light for continu-
ity.
When the main switch is turn to “ON”, the oil
level warning light is come on.

Are the oil level warning light OK?
Replace the meter
assembly.
EAS00802
5. The oil level warning light fails to come on.
YESNO 2. Oil level switch

Drain the engine oil and remove the oil level
switch from the oil pan.

Connect the pocket tester (Ω
100) to the
oil level switch as shown.
Replace the oil level
switch. Positive tester probe

Connector (white)
Negative tester probe
Body ground
1
12

Measure the oil level switch resistance.
Oil level switch resistance
114  126 Ω at 20C (68F)
484  536 Ω at 20C (68F)
1
2

Is the oil level switch OK?
2
When you switch the positive and negative
tester probes, the readings in the above
chart will be reversed.
NOTE:
1
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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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8-48
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
ProCarManuals.com