warning YAMAHA WR 250F 2017 Manual PDF

FUEL INJECTION SYSTEM
9-47
TIP
Disconnect the fuel pump coupler when this diagnostic tool is used.
Fault code No. 39
Item Injector: open or short circuit detected.
Fail-safe systemUnable to start engine
Unable to drive vehicle
Diagnostic code No.36
ActuationActuates injector five times at one-second intervals.
The engine trouble warning light and the “WARNING” on the
Yamaha diagnostic tool screen come on each time the injector is
actuated.
ProcedureCheck that injector is actuated five times by listening for the oper-
ating sound.
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation of service
completion
1 Connection of injector cou-
pler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected 
Connect the coupler securely
or repair/replace the wire har-
ness.Execute the diagnostic mode
(Code No. 36).
No operating sound  Go to
item 2.
Operating sound  Go to
item 6.
2 Defective injector. Measure the fuel injector re-
sistance.
Replace if out of specifica-
tion.
Refer to “CHECKING THE
FUEL INJECTOR” on page 9-
81.Execute the diagnostic mode
(Code No. 36).
No operating sound  Go to
item 3.
Operating sound  Go to
item 6.
3 Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).Improperly connected 
Connect the coupler securely
or repair/replace the wire har-
ness.Execute the diagnostic mode
(Code No. 36).
No operating sound  Go to
item 4.
Operating sound  Go to
item 6.
4 Wire harness continuity. Open or short circuit  Re-
place the wire harness.
Between injector coupler and
ECU coupler.
red/black–red/black
red–red/blueExecute the diagnostic mode
(Code No. 36).
No operating sound  Go to
item 5.
Operating sound  Go to
item 6.
5 Malfunction in ECU. Replace the ECU. —
6 Delete the fault code. — Start the engine and let it idle
for approximately 5 seconds.
Check that the fault code
number is not displayed.

ELECTRICAL COMPONENTS
9-67
EAS27990CHECKING THE BULBS AND BULB SOCK-
ETS
TIP
Do not check any of the lights that use LEDs.
Check each bulb and bulb socket for damage
or wear, proper connections, and also for con-
tinuity between the terminals.
Damage/wear  Repair or replace the bulb,
bulb socket or both.
Improperly connected  Properly connect.
No continuity  Repair or replace the bulb,
bulb socket or both.
Types of bulbs
The bulbs used on this vehicle are shown in the
illustration on the left.
• Bulbs “a” and “b” are used for the headlights
and usually use a bulb holder that must be de-
tached before removing the bulb. The majority
of these types of bulbs can be removed from
their respective socket by turning them coun-
terclockwise.
• Bulbs “c” is used for turn signal and can be re-
moved from the socket by pushing and turn-
ing the bulb counterclockwise.
Checking the condition of the bulbs
The following procedure applies to all of the
bulbs.
1. Remove:
•Bulb
EWA
WARNING
Since the headlight bulb gets extremely hot,
keep flammable products and your hands
away from the bulb until it has cooled down.
ECA
NOTICE
• Be sure to hold the socket firmly when re-
moving the bulb. Never pull the lead, oth-
erwise it may be pulled out of the terminal
in the coupler.
• Avoid touching the glass part of the head-
light bulb to keep it free from oil, otherwise
the transparency of the glass, the life of
the bulb, and the luminous flux will be ad-
versely affected. If the headlight bulb gets
soiled, thoroughly it with a cloth moist-
ened with alcohol or lacquer thinner.
2. Check:
• Bulb (for continuity)
(with the pocket tester)
No continuity  Replace.
TIP
Before checking for continuity, set the pocket
tester to “0” and to the “ 1” range.
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a. Connect the positive tester probe to terminal
“1” and the negative tester probe to terminal
“2”, and check the continuity.
b. Connect the positive tester probe to terminal
“1” and the negative tester probe to terminal
“3”, and check the continuity.
c. If either of the readings indicate no continu-
ity, replace the bulb.
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Pocket tester
90890-03112
Analog pocket tester
YU-03112-C

ELECTRICAL COMPONENTS
9-68
Checking the condition of the bulb sockets
The following procedure applies to all of the
bulb sockets.
1. Check:
• Bulb socket (for continuity)
(with the pocket tester)
No continuity  Replace.
TIP
Check each bulb socket for continuity in the
same manner as described in the bulb section;
however, note the following.
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a. Install a good bulb into the bulb socket.
b. Connect the pocket tester probes to the re-
spective leads of the bulb socket.
c. Check the bulb socket for continuity. If any of
the readings indicate no continuity, replace
the bulb socket.
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EAS2GBB384CHECKING THE FUSES
The following procedure applies to all of the
fuses.
ECA
NOTICE
To avoid a short circuit, always turn off the
meter when checking or replacing a fuse.
1. Remove:
• Side cover (left/right)
• Seat
Refer to “GENERAL CHASSIS” on page 5-
1.
2. Check:
• Main fuse “1”
• Radiator fan motor fuse “2”
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a. Connect the pocket tester to the fuse and
check the continuity.
TIP
Set the pocket tester selector to “ 1”.
b. If the pocket tester indicates “”, replace the
fuse.
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3. Replace:
• Fuse
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a. The meter light goes off.
b. Install a new fuse of the correct amperage
rating.
c. Turn on the meter light to verify if the electri-
cal circuit is operational.
d. If the fuse immediately blows again, check
the electrical circuit.
EWA
WARNING
Never use a fuse with an amperage rating
other than that specified. Improvising or us-
ing a fuse with the wrong amperage rating
may cause extensive damage to the electri-
cal system, cause the lighting and ignition
systems to malfunction and could possibly
cause a fire.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
1
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
FusesAmper-
age ratingQ’ty
Main 15 A 1
Spare 15 A 1
Radiator fan motor 5 A 1
2

ELECTRICAL COMPONENTS
9-69
4. Install:
• Seat
• Side cover (left/right)
Refer to “GENERAL CHASSIS” on page 5-
1.
EAS2GBB385CHECKING AND CHARGING THE BATTERYEWA
WARNING
Batteries generate explosive hydrogen gas
and contain electrolyte which is made of
poisonous and highly caustic sulfuric acid.
Therefore, always follow these preventive
measures:
• Wear protective eye gear when handling or
working near batteries.
• Charge batteries in a well-ventilated area.
• Keep batteries away from fire, sparks or
open flames (e.g., welding equipment,
lighted cigarettes).
• DO NOT SMOKE when charging or han-
dling batteries.
• KEEP BATTERIES AND ELECTROLYTE
OUT OF REACH OF CHILDREN.
• Avoid bodily contact with electrolyte as it
can cause severe burns or permanent eye
injury.
FIRST AID IN CASE OF BODILY CONTACT:
EXTERNAL
• Skin — Wash with water.
• Eyes — Flush with water for 15 minutes
and get immediate medical attention.
INTERNAL
• Drink large quantities of water or milk fol-
lowed with milk of magnesia, beaten egg
or vegetable oil. Get immediate medical at-
tention.
ECA
NOTICE
• This is a VRLA (Valve Regulated Lead Ac-
id) battery. Never remove the sealing caps
because the balance between cells will not
be maintained and battery performance
will deteriorate.
• Charging time, charging amperage and
charging voltage for a VRLA (Valve Regu-
lated Lead Acid) battery are different from
those of conventional batteries. The VRLA
(Valve Regulated Lead Acid) battery
should be charged according to the appro-
priate charging method. If the battery is
overcharged, the electrolyte level will drop
considerably. Therefore, take special care
when charging the battery.
TIP
Since VRLA (Valve Regulated Lead Acid) bat-
teries are sealed, it is not possible to check the
charge state of the battery by measuring the
specific gravity of the electrolyte. Therefore, the
charge of the battery has to be checked by
measuring the voltage at the battery terminals.
1. Remove:
• Side cover (left/right)
• Seat
Refer to “GENERAL CHASSIS” on page 5-
1.
2. Disconnect:
• Battery leads
(from the battery terminals)
ECA
NOTICE
First, disconnect the negative battery lead
“1”, and then positive battery lead “2”.
3. Remove:
• Battery
4. Check:
• Battery charge
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a. Connect a pocket tester to the battery termi-
nals.
TIP
• The charge state of a VRLA (Valve Regulated
Lead Acid) battery can be checked by mea-
suring its open-circuit voltage (i.e., the voltage
when the positive battery terminal is discon-
nected).
• No charging is necessary when the open-cir-
cuit voltage equals or exceeds 12.8 V.
b. Check the charge of the battery, as shown in
the charts and the following example. • Positive tester probe 
positive battery terminal
• Negative tester probe 
negative battery terminal
1
2

ELECTRICAL COMPONENTS
9-70
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5. Charge:
• Battery
(refer to the appropriate charging method)
EWA
WARNING
Do not quick charge a battery.
ECA
NOTICE
• Do not use a high-rate battery charger
since it forces a high-amperage current
into the battery quickly and can cause bat-
tery overheating and battery plate dam-
age.
• If it is impossible to regulate the charging
current on the battery charger, be careful
not to overcharge the battery.• When charging a battery, be sure to re-
move it from the vehicle. (If charging has
to be done with the battery mounted on the
vehicle, disconnect the negative battery
lead from the battery terminal.)
• To reduce the chance of sparks, do not
plug in the battery charger until the battery
charger leads are connected to the bat-
tery.
• Before removing the battery charger lead
clips from the battery terminals, be sure to
turn off the battery charger.
• Make sure the battery charger lead clips
are in full contact with the battery terminal
and that they are not shorted. A corroded
battery charger lead clip may generate
heat in the contact area and a weak clip
spring may cause sparks.
• If the battery becomes hot to the touch at
any time during the charging process, dis-
connect the battery charger and let the
battery cool before reconnecting it. Hot
batteries can explode!
• As shown in the following illustration, the
open-circuit voltage of a VRLA (Valve Reg-
ulated Lead Acid) battery stabilizes about
30 minutes after charging has been com-
pleted. Therefore, wait 30 minutes after
charging is completed before measuring
the open-circuit voltage.
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Charging method using a variable-cur-
rent (voltage) charger
a. Measure the open-circuit voltage prior to
charging. Example
Open-circuit voltage = 12.0 V
Charging time = 6.5 hours
Charge of the battery = 20–30 %
A. Open-circuit voltage (V)
B. Charging time (hours)
C. Relationship between the open-circuit voltage
and the charging time at 20 °C (68 °F)
D. These values vary with the temperature, the
condition of the battery plates, and the electro-
lyte level.
A. Open-circuit voltage (V)
B. Charging condition of the battery (%)
C. Ambient temperature 20 °C (68 °F)
A. Open-circuit voltage (V)
B. Time (minutes)
C. Charging
D. Ambient temperature 20 °C (68 °F)
E. Check the open-circuit voltage.

ELECTRICAL COMPONENTS
9-76
CHECKING THE STARTER MOTOR OPERA-
TION
1. Check:
• Starter motor operation
Does not operate  Perform the electric
starting system troubleshooting, starting
with step 4.
Refer to “ELECTRIC STARTING SYSTEM”
on page 9-6.
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a. Connect the positive battery terminal “1” and
starter motor lead “2” with a jumper lead “3”.
EWA
WARNING
• A wire that is used as a jumper lead must
have at least the same capacity of the bat-
tery lead, otherwise the jumper lead may
burn.
• This check is likely to produce sparks,
therefore, make sure no flammable gas or
fluid is in the vicinity.
b. Check the starter motor operation.
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EAS28150CHECKING THE STATOR COIL
1. Disconnect:
• Stator coil coupler
(from the wire harness)
2. Check:
• Stator coil resistance
Out of specification  Replace the stator
coil.
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a. Connect the pocket tester ( 1) to the sta-
tor coil coupler as shown.b. Measure the stator coil resistance.
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EAS2GBB394CHECKING THE RECTIFIER/REGULATOR
1. Check:
• Charging voltage
Out of specification  Replace the rectifier/
regulator.
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a. Set the digital tachometer to the ignition coil.
b. Connect the pocket tester (DC 20 V) to the
rectifier/regulator coupler as shown. Stator coil resistance
0.528–0.792  (W–W)
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
White “1”
• Negative tester probe 
White “2”
• Positive tester probe 
White “1”
• Negative tester probe 
White “3”
• Positive tester probe 
White “2”
• Negative tester probe 
White “3”
Regulated voltage (DC)
14.1–14.9 V
Digital tachometer
90890-06760
Digital tachometer
YU-39951-B
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Red “1”
• Negative tester probe 
Black “2”
123

ELECTRICAL COMPONENTS
9-78
EAS2GBB397CHECKING THE RESISTER
1. Disconnect:
• Resister coupler
(from the wire harness)
2. Check:
• Resister resistance
Out of specification  Replace the resister.
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a. Connect the pocket tester ( 10) to the re-
sister as shown.
b. Measure the resistance of the resister.
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EAS2GBB398CHECKING THE RADIATOR FAN MOTOR
1. Check:
• Radiator fan motor
Faulty/rough movement  Replace.
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a. Disconnect the radiator fan motor coupler
from the wire harness.
b. Connect the battery (DC 12 V) as shown.c. Measure the radiator fan motor movement.
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EAS2GBB399CHECKING THE COOLANT TEMPERATURE
SENSOR
1. Remove:
• Coolant temperature sensor
EWA
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.
2. Check:
• Coolant temperature sensor resistance
Out of specification  Replace.
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a. Connect the pocket tester ( 1k/100) to
the coolant temperature sensor. Resister resistance
64.6–71.4 
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Black “1”
• Negative tester probe 
Black “2”
• Positive battery terminal 
Blue “1”
• Negative battery terminal 
Black “2”
1
2
Coolant temperature sensor re-
sistance
2512–2777  at 20 °C (2512–
2777  at 68 °F)
210–220  at 100 °C (210–220 
at 212 °F)
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Green/White “1”
• Negative tester probe 
Black/Blue “2”
12
12V
LB

ELECTRICAL COMPONENTS
9-79
b. Immerse the coolant temperature sensor in
a container filled with coolant.
TIP
Make sure the coolant temperature sensor ter-
minals do not get wet.
c. Place a thermometer in the coolant.
d. Slowly heat the coolant, and then let it cool
to the specified temperature indicated in the
table.
e. Check the coolant temperature sensor for
continuity at the temperatures indicated in
the table.
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EAS2GBB400CHECKING THE THROTTLE POSITION
SENSOR
1. Remove:
• Throttle position sensor
(from the throttle body)
EWA
WARNING
• Handle the throttle position sensor with
special care.
• Never subject the throttle position sensor
to strong shocks. If the throttle position
sensor is dropped, replace it.
2. Check:
• Throttle position sensor maximum resis-
tance
Out of specification  Replace.
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a. Connect the pocket tester ( 1k) to the
throttle position sensor.
b. Check the throttle position sensor maximum
resistance.
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3. Install:
• Throttle position sensor
TIP
When mounting the throttle position sensor, ad-
just its angle properly. Refer to “ADJUSTING
THE THROTTLE POSITION SENSOR” on
page 8-11.
12
G/W B/L
B/L G/W
Resistance
6.30 k
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Blue “1”
• Negative tester probe 
Black/Blue “2”
21

ELECTRICAL COMPONENTS
9-80
EAS2GBB401CHECKING THE THROTTLE POSITION
SENSOR INPUT VOLTAGE
1. Check:
• Throttle position sensor input voltage
Out of specification  Replace the ECU.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect the test harness S-pressure sensor
(3P) to the throttle position sensor coupler
and the wire harness.
b. Connect the pocket tester (20 VDC) to the
test harness S-pressure sensor (3P).
c. Start the engine.
d. Measure the throttle position sensor input
voltage.
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EAS2GBB402CHECKING THE INTAKE AIR PRESSURE
SENSOR
1. Check:
• Intake air pressure sensor output voltage
Out of specification  Replace.
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a. Connect the pocket tester (20 VDC) to the
intake air pressure sensor coupler (wire har-
ness side).
b. Start the engine.
c. Measure the intake air pressure sensor out-
put voltage.
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EAS2GBB403CHECKING THE INTAKE AIR TEMPERA-
TURE SENSOR
1. Remove:
• Intake air temperature sensor
(from the air filter case)
EWA
WARNING
• Handle the intake air temperature sensor
with special care.
• Never subject the intake air temperature
sensor to strong shocks. If the intake air
temperature sensor is dropped, replace it.
2. Check:
• Intake air temperature sensor resistance
Out of specification  Replace. Throttle position sensor input
voltage
4–6 V
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
Test harness S– pressure sensor
(3P)
90890-03207
Test harness S– pressure sensor
(3P)
YU-03207
• Positive tester probe 
Blue “1”
• Negative tester probe 
Black/Blue “2”
21
Intake air pressure sensor output
voltage
3.61–3.67 V at 101.3 kPa (3.61–
3.67 V at 1.01kgf/cm
2, 3.61–3.67
V at 14.7 psi)
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Pink “1”
• Negative tester probe 
Black/Blue “2”
12

LIST OF SELF-DIAGNOSTIC AND FAIL-SAFE ACTIONS
10-7
*1: Symbols used in the explanations of the malfunction history
: Normal
: There is currently a malfunction or abnormal condition.
: A malfunction or abnormal condition occurred previously, but the affected system or component
is currently operating normally.
ACTUATOR OPERATION TABLE62 Malfunction history ( )
code erasure *1
• There is no history.
• There is some history.•00
• Other: Displays the total
number of ( ) and ( ).Replace all ( ) with ( )
by the operation start pro-
cessing.
64 Setting history display
• There is no history.
• There is some history.
• History is unknown (Histo-
ry data is damaged).Displays the presence or ab-
sence of the setting history by
Power Tuner.
•00
•01
•02—
65 Setting map erasure
• There is no setting.
• There is some setting.Displays the presence or ab-
sence of the setting history by
Power Tuner.
•00
•01Erase all setting maps by
the operation start process-
ing.
70 Program version number Displays a program version
No.—
Diag-
nostic
code
No.Item Actuation Procedure
30 Ignition coil Actuates the ignition coil five
times at one-second inter-
vals.
“WARNING” on the Yamaha
diagnostic tool blinks five
times when the ignition coil is
actuated.Check that a spark is gener-
ated five times.
• Connect an ignition
checker.
36 Injector Actuates the injector five
times at one-second inter-
vals.
“WARNING” on the Yamaha
diagnostic tool blinks five
times when the radiator fan
motor relay is actuated.TIP: Before performing
this operation, be sure to
disconnect the fuel pump
coupler.
Check that injector is actu-
ated five times by listening
for the operating sound. Diag-
nostic
code
No.Item Display Procedure