Yamaha F150B, Service Manual

Page: 146 / 458

5-21
ELEC
Electrical system
Checking the water pressure sensor
(option)
1. Disconnect the water pressure sensor
coupler
a
.
2. Turn the engine start switch to “ON,” and
then measure the input voltage at the
water pressure sensor coupler.
3. Remove the water pressure sensor, and
then connect the pressure pump
a
and
test harness (3 pins)
b
.
4. Apply positive pressure to the water pres-
sure sensor slowly, and then measure
the output voltage.
5. Turn the engine start switch to “OFF,” and
then disconnect the test harness
b
and
pressure pump
a
.
6. Remove the junction box cover, and then
disconnect the engine ECM coupler
b
.
7. Check the wiring harness for continuity.
8. Install the water pressure sensor, and
then connect the water pressure sensor
coupler
a
.
9. Connect the engine ECM coupler
b
, and
then install the junction box cover.
Water pressure sensor input voltage
(reference data):
Orange (O)–Black (B)
4.75–5.25 V
Pressure pump
a
:
(commercially available)
Test harness (3 pins)
b
: 90890-06869
a
B O
B
B G
G/W
O
L/W
a
b
b
Water pressure sensor output voltage:
Blue/White (L/W)–Black (B)
2.5 V at 392.0 kPa
(3.92 kgf/cm
2 , 56.8 psi)
4.5 V at 784.0 kPa
(7.84 kgf/cm
2 , 113.7 psi)
Wiring harness continuity:
Terminal 1–Terminal 10
Terminal 2–Terminal 8
Terminal 3–Terminal 11
b
10 8 11
1 3 2
a
b