Checking The Throttle Position Sensor Input Voltage; Checking The Intake Air Temperature Sensor - Yamaha YZ450FX 2019 Owner's Service Manual

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EAM30305
CHECKING THE THROTTLE POSITION
SENSOR INPUT VOLTAGE
1. Check:
• Throttle position sensor input voltage
Out of specification  Replace the ECU.
Throttle position sensor input
voltage
4–6 V
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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 digital circuit tester (DCV) to the
test harness S– pressure sensor (3P).
Digital circuit tester (CD732)
90890-03243
Model 88 Multimeter with tachom-
eter
YU-A1927
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"
ELECTRICAL COMPONENTS
c. Start the engine.
d. Measure the throttle position sensor input
voltage.
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EAM30307
CHECKING THE INTAKE AIR
TEMPERATURE SENSOR
1. Remove:
• Intake air temperature sensor
(from the air filter case)
EWA14110
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.
Intake air temperature sensor re-
sistance
5400–6600  at 0 C (5400–6600
 at 32 F)
Intake air temperature sensor re-
sistance
290–390 
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a. Connect the digital circuit tester () to the in-
take air temperature sensor terminal.
Digital circuit tester (CD732)
90890-03243
Model 88 Multimeter with tachom-
eter
YU-A1927
• Positive tester probe 
Brown/White "1"
• Negative tester probe 
Black/Blue "2"
8-67
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