sensor YAMAHA WR 250F 2016 Workshop Manual

FUEL INJECTION SYSTEM
9-45
2 Installed condition of lean an-
gle sensor.Check the installed direction
and condition of the sensor.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 3.
3 Defective lean angle sensor. Execute the diagnostic mode.
(Code No. 08)
Replace if defective.
Refer to “CHECKING THE
LEAN ANGLE SENSOR” on
page 9-75.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 4.
4 Malfunction in ECU. Replace the ECU.
Fault code No. 33
ItemIgnition coil: open or short circuit detected in the primary lead
of the ignition coil.
Fail-safe systemUnable to start engine
Unable to drive vehicle
Diagnostic code No.30
ActuationActuates the ignition coil 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 ignition coil
is actuated.
ProcedureCheck that a spark is generated five times.
• Connect an ignition checker.
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation of service
completion
1 Connection of ignition coil
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.Start the engine and let it idle
for approximately 5 seconds.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 2.
2 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.Start the engine and let it idle
for approximately 5 seconds.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 3. Fault code No. 30
Item Latch up detected.

FUEL INJECTION SYSTEM
9-46
3 Connection of sub wire har-
ness coupler.Check the lock-
ing condition of the
coupler.Disconnect the cou-
pler and check the pins (bent
or broken terminals and lock-
ing condition of the pins).Improperly connected 
Connect the coupler secure-
lyor repair/replace the sub
wire harness.Start the engine and let it idle
for approximately 5 seconds.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 4.
4 Wire harness continuity. Open or short circuit  Re-
place the wire harness.
Between ignition coil coupler
and ECU coupler.
orange–orangeStart the engine and let it idle
for approximately 5 seconds.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 5.
5 Installed condition of ignition
coil.
Check for looseness or
pinching.Improperly installed sensor
 Reinstall or replace the
sensor.Start the engine and let it idle
for approximately 5 seconds.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 6.
6 Defective ignition coil. (test
the primary coils for continu-
ity)Check the ignition coil.
Replace if defective.
Refer to “CHECKING THE
IGNITION COIL” on page 9-
74.Start the engine and let it idle
for approximately 5 seconds.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 7.
7 Malfunction in ECU. Execute the diagnostic mode
(diagnostic code No. 30).
No spark  Replace the
ECU. Fault code No. 33
ItemIgnition coil: open or short circuit detected in the primary lead
of the ignition coil.

FUEL INJECTION SYSTEM
9-48
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay.
Fault code No. 41
Item Lean angle sensor: open or short circuit detected.
Fail-safe systemUnable to start engine
Able to drive vehicle
Diagnostic code No.08
Diagnostic tool displayLean angle sensor output voltage
• 0.4–1.4 (upright)
• 3.7–4.4 (overturned)
ProcedureRemove the lean angle sensor and incline it more than 45 degrees.
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation of service
completion
1 Connection of lean angle
sensor 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.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 2.
2 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.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 3.
3 Wire harness continuity. Open or short circuit  Re-
place the wire harness.
Between lean angle sensor
coupler and ECU coupler.
blue–blue
yellow/green–yellow/green
black/blue–black/bluePush the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 4.
4 Defective lean angle sensor. Execute the diagnostic mode.
(Code No. 08)
Replace if defective.
Refer to “CHECKING THE
LEAN ANGLE SENSOR” on
page 9-75.Push the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 5.
5 Malfunction in ECU. Replace the ECU.

ELECTRICAL COMPONENTS
9-63
1. Intake air temperature sensor
2. Intake air pressure sensor
3. Throttle position sensor
4. Starter relay
5. Main fuse
6. Headlight relay
7. Starting circuit cut-off relay
8. Lean angle sensor
9. Radiator fan motor fuse
10.Radiator fan motor relay
11.Main relay
12.Coolant temperature sensor

ELECTRICAL COMPONENTS
9-74
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a. Connect the pocket tester ( 1k) to the
spark plug cap.
b. Measure the spark plug cap resistance.
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EAS2GB7390CHECKING THE IGNITION COIL
1. Disconnect:
• Ignition coil terminal
(from the sub wire harness)
• Spark plug cap
(from the ignition coil)
2. Check:
• Primary coil resistance
Out of specification  Replace.
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a. Connect the pocket tester ( 1) to the igni-
tion coil.b. Measure the primary coil resistance.
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3. Check:
• Secondary coil resistance
Out of specification  Replace.
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a. Connect the pocket tester ( 1k) to the ig-
nition coil.
b. Measure the secondary coil resistance.
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EAS2GB7391CHECKING THE CRANKSHAFT POSITION
SENSOR
1. Disconnect:
• Crankshaft position sensor coupler
(from the wire harness)
2. Check:
• Crankshaft position sensor resistance Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
Primary coil resistance
2.16–2.64 
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Ignition coil terminal 1 “1”
• Negative tester probe 
Ignition coil terminal 2 “2”
Secondary coil resistance
8.64–12.96 k
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Ignition coil terminal 1 “1”
• Negative tester probe 
Spark plug lead “2”

ELECTRICAL COMPONENTS
9-75
Out of specification  Replace.
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a. Connect the pocket tester ( 100) to the
crankshaft position sensor coupler.
b. Measure the crankshaft position sensor re-
sistance.
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EAS2GB7392CHECKING THE LEAN ANGLE SENSOR
1. Remove:
• Lean angle sensor
(from the bracket)
2. Check:
• Lean angle sensor output voltage
Out of specification  Replace.
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a. Connect the lean angle sensor coupler to
the wire harness.
b. Connect the pocket tester (DC 20 V) to the
lean angle sensor coupler as shown.c. Incline the lean angle sensor.
d. Measure the lean angle sensor output volt-
age.
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EAS2GB7393CHECKING THE STARTER MOTOR OPERA-
TION
1. Check:
• Coolant temperature sensor
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
• 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. Crankshaft position sensor resis-
tance
228–342  (Gy–B)
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Gray “1”
• Negative tester probe 
Black “2”
Lean angle sensor output voltage
Less than 45° “a”
0.4–1.4V
More than 45° “b”
3.7–4.4V
12
Gy B
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
Test harness– lean angle sensor
(6P)
90890-03209
Test harness– lean angle sensor
(6P)
YU-03209
• Positive tester probe 
Yellow/Green “1”
• Negative tester probe 
Black/Blue “2”
2 1
aa
bON ON

ELECTRICAL COMPONENTS
9-77
EAS2GB7395CHECKING THE SPEED SENSOR
1. Check:
• Speed sensor output voltage
Out of specification  Replace.
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a. Connect the test harness-speed sensor (3P)
to the speed sensor coupler and wire har-
ness.
b. Connect the pocket tester (DC20V) to the
test harness-speed sensor (3P).
c. Push the start switch.
d. Elevate the front wheel and slowly turn it.
e. Measure the voltage (DC 5 V) of white and
black/white. With the front wheel slowly ro-
tating, voltage alternates between 0 V and 5
V.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲EAS2GB7396CHECKING THE FUEL SENDER
1. Drain the gasoline.
2. Disconnect:
• Fuel sender coupler
(from the fuel sender)
3. Remove:
• Fuel sender
(from the fuel tank)4. Check:
• Fuel sender resistance
Out of specification  Replace the fuel
sender.
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a. Connect the pocket tester ( 1k) to the
fuel sender as shown.
b. Measure the resistance of the fuel sender.
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EAS2GB7397CHECKING 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. Output voltage reading cycle
0.6V to 4.8V to 0.6V to 4.8V
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
Test harness– speed sensor 5TJ
(3P)
90890-03228
Test harness– speed sensor 5TJ
(3P)
YU-03228
• Positive tester probe 
White “1”
• Negative tester probe 
Black “2”
BRW
21
Fuel sender resistance
1.35–1.90 k at 25°C (77°F)
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Green “1”
• Negative tester probe 
Black “2”
Resister resistance
64.6–71.4 
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
1
2

ELECTRICAL COMPONENTS
9-78
b. Measure the resistance of the resister.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲EAS2GB7398CHECKING 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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EAS2GB7399CHECKING 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.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect the pocket tester ( 1k/100) to
the coolant temperature sensor.
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. • Positive tester probe 
Black “1”
• Negative tester probe 
Black “2”
• Positive battery terminal 
Blue “1”
• Negative battery terminal 
Black “2”
1
2
12
12V
LB
Coolant temperature sensor re-
sistance
2.51–2.78 k at 20 °C (2.51–2.78
k at 68 °F)
210–221  at 100 °C (210–221 
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
G/W B/L
B/L G/W

ELECTRICAL COMPONENTS
9-79
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EAS2GB7400CHECKING 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.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
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.
EAS2GB7401CHECKING THE THROTTLE POSITION
SENSOR INPUT VOLTAGE
1. Check:
• Throttle position sensor input voltage
Out of specification  Replace the ECU.
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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). 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”
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
21

ELECTRICAL COMPONENTS
9-80
c. Start the engine.
d. Measure the throttle position sensor input
voltage.
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EAS2GB7402CHECKING 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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EAS2GB7403CHECKING 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.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect the pocket tester ( 1k/100) to
the intake air temperature sensor terminal. • Positive tester probe 
Blue “1”
• Negative tester probe 
Black/Blue “2”
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”
21
Intake air temperature sensor re-
sistance
290–390  at 80 °C (290–390 
176 °F)
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
• Positive tester probe 
Brown/White “1”
• Negative tester probe 
Black/Blue “2”
12