Mitsubishi 3000gt 1997 - ABS OPERATION CHECK AND ADJUSTMENT; Wheel Speed Sensor Output Voltage Check; Inspecting Wave Forms With An Oscilloscope

35-20
SERVICE
BRAKES
-
Service
Adiustment
Procedures
Main
wiring
harness
M8991638
i4co13o
SERVICE
ADJUSTMENT
PROCEDURES
ABS
OPERATION
CHECK
WHEEL
SPEED
SENSOR
OUTPUT
VOLTAGE
CHECK
1.
Lift up
the
vehicle
and
release
the
parking
brake.
2. Disconnect
the ECU
harness
connector
and
use
the
specialtool
to measure
from
the
harness
side
connector'
3.
iotate
the
wheel
to be
measured
at
approximately
112-1
rotation
per
second,
and
check
the output
voltage using
a
circuit
tester
or an
oscilloscope.
Wheel
speed
sensor
Front
left
Front
right
Rear
left
Rear
right
Terminal
No.
19
14
16
18
20
15
17
46
Output
voltage
When
measuring
with a
circuit
tester:
70 mV or
more
When
measuring
with an
oscilloscope:
100
mV
P-P
or
more
lf the output
voltage
is lower
than
the
above
values,
the
reason
could
be as
follow:
o
Faulty
wheel
speed
sensor.
So
replace
the
wheel sPeed
sensor.
Inspecting
Wave
Forms
With An Oscilloscope
Use
the
following
method
to observe
the output
voltage
wave
form
from each
wheel sensor
with an
oscilloscope .
o
Start
the engine,
and
rotate
the
front
wheels by
engaging
1st
gear
(vehicles with manual
transmission)
or
D
range
(vehicles
with automatic
transmission).
Turn the
rear
wheels
manually
so
that they
rotate
at a
constant
speed.
NOTE
1.
Check
the connection
of
the
sensor
harness
and
connector
before
using
the
oscilloscope.
2.
The
wave
form
measurements
can
also
be taken
while
the
vehicle
is
actually
moving.
3.
The output
voltage will be
small
when the
wheel
speed
is
low, and
similarly
it will be
large
when the
wheel
speed
is
high.
4.