Electrical Components - Yamaha YZ450F Owner's Service Manual

ELECTRICAL
COMPONENTS
CHECKING THE COOLANT
TEMPERATURE SENSOR
1. Remove:
•Coolant temperature sensor
Refer to "REMOVING THE CYL-
INDER HEAD" section in the
CHAPTER 4.
• Handle the coolant temperature
sensor with special care.
• Never subject the coolant tem-
perature sensor to strong
shocks. If the coolant tempera-
ture sensor is dropped, replace
it.
2. Check:
• Coolant temperature sensor re-
sistance
3. Connect:
• Tester
Tester (+) lead → Brown lead "1"
Tester (-) lead → Black/Blue lead
"2"
4. Immerse the coolant temperature
sensor in a container filled with
coolant.
Make sure the coolant temperature
sensor terminals do not get wet.
5. Place a thermometer "3" in the
coolant.
6. Slowly heat the coolant, and then
let it cool to the specified temper-
ature indicated in the table.
Coolant
tempera-
ture sensor
resistance
210–220 Ω
(100°C,
212°F)
2.51–2.78
kΩ (20°C,
68°F)
Out of specification → Replace.
CHECKING THE INTAKE AIR
PRESSURE SENSOR
1. Check:
• Intake air pressure sensor output
voltage
2. Connect:
• Test harness S–pressure sensor
(3P) "1"
• Tester
Tester (+) lead → Pink/White lead
(wire harness color)
Tester (-) lead → Black/Blue lead
(wire harness color)
Test harness S–pressure
sensor (3P)
YU-03207/90890-03207
Br B/L
3. Connect the FI diagnostic tool
sub-wire harness to a battery, and
then set the switch on the harness
to "ON".
When checking the intake air pres-
sure sensor, do not start the en-
gine.
4. Measure the intake air pressure
sensor output voltage.
Output volt-
3.4–3.8 V
Out of specification → Replace

ELECTRICAL COMPONENTS

Tester se-
lector posi-
tion
Ω×100
kΩ×1
Tester se-
lector posi-
age
tion
DCV
7-36
CHECKING THE INTAKE AIR
TEMPERATURE SENSOR
1. Remove:
• Intake air temperature sensor
(from the air filter case. )
• Handle the intake air temperature
sensor with special care.
• Never subject the intake air tem-
perature sensor to strong
shocks. If the intake air tempera-
ture sensor is dropped, replace
it.
2. Check:
• Intake air temperature sensor re-
sistance
3. Connect:
• Tester
Tester (+) lead → Brown/White
lead "1"
Tester (-) lead → Black/Blue lead
(wire harness color) "2"
Intake air
Tester se-
tempera-
lector posi-
ture sensor
resistance
5.4–6.6 kΩ
(0°C, 32°F)
290–390 Ω
(80°C,
176°F)
Out of specification → Replace.
CHECKING THE ATMOSPHERIC
PRESSURE SENSOR
1. Check:
• Atmospheric pressure sensor out-
put voltage
2. Connect:
• Test harness S- pressure sensor
(3P) "1"
• Tester
Tester (+) lead → Pink lead (wire
harness color)
Tester (-) lead → Black/Blue lead
(wire harness color)
Br/W B/L
tion
kΩ×1
Ω×100