Mitsubishi Lancer Evolution IX. Manual - part 618
ON-VEHICLE SERVICE
MANUAL TRANSMISSION (FF)
22A-155
2. Rotate the measured wheel by about 1/2 to 1
rotations/second, and check the output voltage
between the following terminals using a circuit
tester (AC mV range) or oscilloscope.
Output voltage:
Above 70 mV when measured with the circuit
tester
Above 200 mVP-P when measured with the
oscilloscope
3. If the output voltage is lower than the above
values, the following reasons may be suspected.
Check or replace the wheel speed sensor.
• Excessive clearance between the ball piece of
the wheel speed sensor and ABS rotor
• Wheel speed sensor fault
INSPECTION PROCEDURE USING
OSCILLOSCOPE
After checking the connected state of the harness of
the wheel speed sensor and connector, and measure
the output voltage waveform of each wheel speed
sensor on the oscilloscope as follows.
Start the engine, shift the transmission to the 1st
gear to rotate the driving wheel, and rotate the
non-driving wheel at constant velocity with the hand.
NOTE:
.
•
It is also possible to actually drive the vehicle and
observe the waveform.
•
The output voltage is low if the wheel speed is
low and gradually increases as the speed
increases.
CAUTION
As the wheel speed sensor cable follows the
movement of the front or rear suspension, it will
change considerably on poor condition roads.
Therefore, also observe the output voltage wave-
form of the wheel speed sensor with the sensor
harness vibrated to simulate special conditions
such as driving in poor road conditions.
Front left
Front right Rear left
Rear right
Terminal
No.6 and
No.19
Terminal
No.9 and
No.22
Terminal
No.8 and
No.21
Terminal
No.7 and
No.20
AC310853
When rotated with the hand
When idling (5 - 6 km/h) 1st gear
10.0 ms/DIV
1 V/DIV
AB