Yamaha YP400T Service Manual page 325

THROTTLE BODY AND FUEL INJECTOR
Y/L B/L L
3 2 1
Positive tester probe → blue terminal 1
Negative tester probe →
Pocket tester
90890-03112, YU-03112-C
b. Measure the throttle position sensor volt-
age.
Out of specification → Replace or repair the
wire harness.
Throttle position sensor voltage
5 V
(blue–black/blue)
c. Connect the pocket tester (DC 20 V) to the
terminals of the throttle position sensor.
Positive tester probe →
Negative tester probe →
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.
Throttle position sensor voltage
(closed position)
0.4 ~ 0.9 V
(yellow/blue–black/blue)
L LLL L LLL L L LLL L
7 - 35
FI
black/blue terminal 2
yellow/blue terminal 3
black/blue terminal 2
L LLL L L LLL L L LLL L LLL