Yamaha F150B, Service Manual

Page: 158 / 458

5-33
ELEC
Electrical system
4. Connect the special service tool
a
and
test harness (3 pins)
b
.
5. Apply negative pressure to the air pres-
sure sensor slowly, and then measure
the output voltage.
TIP:
When checking the air pressure sensor, do
not start the engine.
6. Turn the engine start switch to “OFF,” and
disconnect the special service tool
a
and test harness
b
.
7. Remove the junction box cover, and then
disconnect the engine ECM coupler
b
.
8. Check the wiring harness for continuity.
9. Connect the engine ECM coupler
b
, and
then install the junction box cover.
10. Connect the air pressure sensor coupler
a
.
Checking the engine temperature
sensor
1. Disconnect the engine temperature sen-
sor coupler
a
.
2. Turn the engine start switch to “ON,” and
then measure the input voltage at the
engine temperature sensor coupler.
Vacuum/pressure pump gauge set
a
:
90890-06756
Test harness (3 pins)
b
: 90890-06869
Air pressure sensor output voltage:
Pink/Green (P/G)–Black (B)
3.21 V at –20.0 kPa
(–0.20 kgf/cm 2 , –2.9 psi)
2.16 V at –46.7 kPa
(–0.467 kgf/cm 2 , –6.8 psi)
B
B
G G/W
O
a
b
b
P/G
Wiring harness continuity:
Terminal 1–Terminal 10
Terminal 2–Terminal 8
Terminal 3–Terminal 33
b
10 8
33
1 3 2
a
b