Checking The Intake Air Temperature Sensor; Checking The Fuel Injector - Yamaha UMAX Service Manual

b. Connect the digital circuit tester to the test
harness S– pressure sensor 5S7 (3P).
Test harness S– pressure sensor
5S7 (3P)
90890-03207
Test harness S– pressure sensor
5S7 (3P)
YU-03207
Digital circuit tester (CD732)
90890-03243
Model 88 Multimeter with ta-
chometer
YU-A1927
• Positive tester probe →
green (wire harness color)
• Negative tester probe →
black/white (wire harness color)
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c. Turn the main switch to "ON".
d. Measure the intake air pressure sensor
output voltage.
CHECKING THE INTAKE AIR
TEMPERATURE SENSOR
1. Remove:
• Intake air temperature sensor
(from the air filter case.)
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.
ELECTRICAL COMPONENTS (YUM1A/YUM2A)
8-58
Intake air temperature sensor re-
sistance
2.21–2.69 kΩ at 20 °C
(2.21–2.69 kΩ at 68 °F)
Intake air temperature sensor re-
sistance (reference data)
0.322 kΩ at 80 °C
(0.322 kΩ at 176 °F)
a. Connect the digital circuit tester to the in-
take air temperature sensor terminals as
shown.
Digital circuit tester (CD732)
90890-03243
Model 88 Multimeter with ta-
chometer
YU-A1927
b. Immerse the intake air temperature sen-
sor "1" in a container filled with water "2".
TIP
Make sure that the intake air temperature sensor
terminals do not get wet.
c. Place a thermometer "3" in the water.
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d. Heat the water or let it cool down to the
specified temperatures.
e. Measure the intake air temperature sen-
sor resistance.

CHECKING THE FUEL INJECTOR

1. Check:
• Fuel injector resistance
Out of specification → Replace the fuel injec-
tor.
Resistance
12.0 Ω
a. Disconnect the fuel injector coupler from
wire harness.
b. Connect the digital circuit tester to the fuel
injector terminals as shown.
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