cooling YAMAHA YZF-R1S 2004 Owner's Manual

7-23
FUEL INJECTION SYSTEMFI
Fault code No.21SymptomOpen or short circuit is detected from the coolant temperature sensor.
Used diagnostic code No. 06 (coolant temperature sensor)
OrderInspection operation item and probable
causeOperation item and countermeasureReinstatement
method
1Connected condition of connector
Inspect the coupler for any pins that
may have pulled out.
Check the locking condition of the
coupler.If there is a malfunction, repair it and connect it
securely.
Coolant temperature sensor coupler
Main wiring harness ECU coupler
Sub-wire harness couplerReinstated by
turning the
main switch
ON.
2Open or short circuit in wiring harness
and / or sub lead.Repair or replace if there is an open or short
circuit.
Between sensor coupler and ECU coupler
Black / Blue – Black / Blue
Green / White – Green / White
3Defective coolant temperature sensor.Execute the diagnostic mode (Code No.06).
Replace if defective.
Refer to “COOLING SYSTEM” in chapter 8.
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COOLING SYSTEMELEC
EAS00807
COOLING SYSTEM
CIRCUIT DIAGRAM
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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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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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COOLING SYSTEMELEC

Remove the coolant temperature sensor.

Connect the pocket tester (Ω
1k) to the
coolant temperature sensor as shown.

Immerse the coolant temperature sensor in
a container filled with coolant .
Make sure the coolant temperature sensor
terminals do not get wet.

Place a thermometer in the coolant.

Slowly heat the coolant, and then let it cool to
the specified temperature indicated in the
table.

Check the coolant temperature sensor for
continuity at the temperatures indicated in
the table.
EAS00812
1
Coolant temperature sensor
resistance
0C (32F): 5.21  6.37 kΩ
80C (176F): 0.29  0.35 kΩ
WARNING

Handle the coolant temperature sensor
with special care.

Never subject the coolant temperature
sensor to strong shocks. If the coolant
temperature sensor is dropped, replace
it.
6. Coolant temperature sensor
Replace the coolant
temperature sensor.
NOYES
Coolant temperature sensor
20 Nm (2.0 m
kg, 14 ft
lb)
Three bond sealock
10

Does the coolant temperature sensor oper-
ate properly?
7. Wiring

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

Is the cooling system’s wiring properly con-
nected and without defects?
Properly connect or
repair the cooling
system’s wiring.
NOYES
This circuit is OK.
EAS00813
2
NOTE:
3
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OVERHEATING / OVERCOOLING /
POOR BRAKING PERFORMANCETRBL
SHTG
FUEL SYSTEM
Throttle body (-ies)

Damaged or loose throttle body joint
Air filter

Clogged air filter element
CHASSIS
Brake(s)

Dragging brake
ELECTRICAL SYSTEMS
Spark plug(s)

Incorrect spark plug gap

Incorrect spark plug heat range
Ignition system

Faulty E.C.U.

Loose union bolt

Damaged brake hose

Oil or grease on the brake disc

Oil or grease on the brake pad

Incorrect brake fluid level
EAS00855
OVERHEATING
ENGINE
Clogged coolant passages

Cylinder head(s) and piston(s)

Heavy carbon buildup
Engine oil

Incorrect oil level

Incorrect oil viscosity

Inferior oil quality
COOLING SYSTEM
Coolant

Low coolant level
Radiator

Damaged or leaking radiator

Faulty radiator cap

Bent or damaged radiator fin
Water pump

Damaged or faulty water pump

Thermostat

Thermostat stays closed

Oil cooler

Clogged or damaged oil cooler

Hose(s) and pipe(s)

Damaged hose

Improperly connected hose

Damaged pipe

Improperly connected pipe
EAS00856
OVERCOOLING
COOLING SYSTEM
Thermostat

Thermostat stays open
EAS00857
POOR BRAKING PERFORMANCE

Worn brake pad

Worn brake disc

Air in hydraulic brake system

Leaking brake fluid

Faulty brake caliper kit

Faulty brake caliper seal
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