2004 YAMAHA YZF-R1S coolant temperature

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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7-35
Order Job / Part Q’ty Remarks
1
2
3
4
5
6
7
8Removing the throttle bodies
Seat
Fuel tank
Air filter case
Sub-wire harness coupler
Coolant temperature sensor coupler
Thermo wax inlet hose
Thermo wax outlet hose
Idle adjust screw wire
Throttle body joint clamp
Throttle bodies
Throttle cables2
1
1
1
1
4
1
2Remove the parts in the order listed.
Refer to “SEAT” in chapter 3.
Refer to “FUEL TANK” in chapter 3.
Refer to “AIR FILTER CASE” in chapter 3.
Disconnect.
Disconnect.
Loosen.
If it loosens too much, the nut will sepa-
rate.
Disconnect.
NOTE:
THROTTLE BODIESFI
THROTTLE BODIES
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7-45
A
THROTTLE BODIESFI
NOTE:
NOTE:
b. After performing the step a, move the sub-
throttle position sensor to adjust to be in a
range from 0.97 to 1.07 V
Sub-throttle position sensor
voltage
0.97
1.07 V
(green / yellow – blue)

After setting up the sub-throttle position sen-
sor, check that the sub-throttle position sensor
output voltage is 0.4 V or more with the nut of
worm shaft turned to the full close side until it
stops.

When the sub-throttle position sensor output
voltage is 0.4 V or more, check that the sub-
throttle position sensor output voltage is 4.6 V
or less with the nut of worm shaft turned to the
full open side until it stops.
CHECKING AND ADJUSTING THE THERMO
WA X
1. Check:

thermo wax
1
Damege
Replace the thermo wax.
2. Adjust:

thermo wax the end face distance
a
a. Before adjusting the distance, push the rod
b in order to be fitted in several times by
hand.
b. Measure the outside air temperature, and
adjust the distance
a by turning the adjust-
ing screw
2. Refer to the thermo wax toler-
ance table based on the measured outside
air temperature for correct adjustment.

Setup tolerance of the longitudinal axis should
be  0.2 mm ( 0.008 in).

After adjusting the thermo wax, check that the
first idling is released at the coolant tempera-
ture around 60C (140F) by idling.

If the first idling is not released around 60C
(140F), make sure to set it again. (When the
coolant temperature is low, adjust the distance
between the end faces longer or adjust it short-
er when the coolant temperature is high.)

In case of turning the adjusting bolt two-third
turn, the temperature varies about 10C
(50F).
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7-46
AIR INDUCTION SYSTEMFI
EAS00507
AIR INDUCTION SYSTEM
AIR INJECTION
The air induction system burns unburned ex-
haust gases by injecting fresh air (secondary
air) into the exhaust port, reducing the emission
of hydrocarbons.
When there is negative pressure at the exhaust
port, the reed valve opens, allowing secondary
air to flow into the exhaust port. The required
temperature for burning the unburned exhaust
gases is approximately 600 to 700C (1112 to
1292F).
EAS0097
AIR CUT-OFF VALVE
The air cut-off valve is controlled by the signals
from the ECU in accordance with the combus-
tion conditions. Ordinarily, the air cut-off valve
opens to allow the air to flow during idle and
closes to cut-off the flow when the motorcycle is
being driven. However, if the coolant tempera-
ture is below the specified value, the air cut-off
valve remains open and allows the air to flow
into the exhaust pipe until the temperature be-
comes higher than the specified value.
AFrom the air cleaner
BTo the cylinder head
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8-2
9Radiator fan motor relay
10Turn signal relay
11Rectifier / regulator
12Throttle position sensor
13Sub-throttle position sensor
1Coolant temperature sensor
2Intake air temperature sensor
3Intake air pressure sensor
4Fuel pump
5ECU
6Lean angle cut-off switch
7Starting circuit cut-off relay
8Headlight relay (dimmer)
ELECTRICAL COMPONENTSELEC
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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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8-44
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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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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