Checking The Air Temperature Sensor - Yamaha F150B Service Manual

ELEC
4. Remove the junction box cover, and then
disconnect the engine ECM coupler b.
.
b
5. Check the wiring harness for continuity.
a
1
b
15 14
Wiring harness continuity:
Terminal 1–Terminal 14
Terminal 2–Terminal 8
Terminal 3–Terminal 15
6. Connect the engine ECM coupler b, and
then install junction box cover.
7. Connect the pulser coil coupler a.

Checking the air temperature sensor

1. Measure the ambient temperature.
2. Connect the YDIS to display "Intake tem-
perature" (air temperature).
5-31
Electrical system
2
3
8
3. Check that the difference between the
ambient temperature and the displayed
intake temperature is within ± 5 °C
(±9 °F).
TIP:
• Check the air temperature sensor when the
engine is cold.
• When checking the air temperature sensor,
remove the top cowling and do not start the
engine.
4. Disconnect the air temperature sensor
coupler a.
5. Turn the engine start switch to "ON," and
then measure the input voltage at the air
temperature sensor coupler.
B B/Y
Air temperature sensor input voltage:
Black/Yellow (B/Y)–Black (B)
4.75–5.25 V
6. Turn the engine start switch to "OFF," and
then remove the air temperature sensor.
7. Place the air temperature sensor in a
container of water and slowly heat the
water.
a