Yamaha 2004 YP400, Service Manual, Page: 336 / 417

7 - 35
FI
THROTTLE BODY AND FUEL INJECTOR
b. Measure the throttle position sensor volt-
age.
Out of specification
→
Replace or repair the
wire harness.
c. Connect the pocket tester (DC 20 V) to the
terminals of the throttle position sensor.
d. While slowly opening the throttle, check that
the throttle position sensor voltage is
increased.
Voltage does not change or it changes
abruptly
→
Replace the throttle position
sensor.
Out of specification (closed position)
→
Replace the throttle position sensor.
▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲▲▲
Positive tester probe
→
blue terminal
1
Negative tester probe
→
black/blue terminal
2
Pocket tester
90890-03112, YU-03112-C
Throttle position sensor voltage
5 V
(blue–black/blue)
Positive tester probe
→
yellow/blue terminal
3
Negative tester probe
→
black/blue terminal
2
Throttle position sensor voltage
(closed position)
0.4 ~ 0.9 V
(yellow/blue–black/blue)
L Y / L B / L
3 1 2