Mitsubishi 3000GT 1991, Service Manual

Page: 779 / 1146

SERVICE BRAKES
Service Adjustment Procedures
i
9 7 5 1
Check connector
ECU
Body harness MB991 356
I
When turned manually
MEASUREMENT OF SPEED SENSOR
OUTPUT VOLTAGE
Lift up the vehicle and release the parking brake.
2. Disconnect the ECU harness connector and measure with
the adapter harness (MB991 356) connected to the harness
side connector.
Caution
1. Never insert a probe, etc. into the connector as it
may result in poor contact later.
2.
Do not connect the connector (Special Tool) marked
except when recording the waveform on a
driving test. In such a case, connect the connector
to the ECU.
Terminal No. (same for AWD and
FL RR FR RL
4
24 21 8
5
26 23
9
3. Manually turning the wheel to be measured by to 1
turn/second, measure the output voltage with a circuit
tester or oscilloscope.
Output voltage:
When measured with circuit tester: 70 or more
When measured with oscilloscope (max. voltage): 100
or more
Probable causes of low output voltage
l
Speed sensor pole piece-to-rotor clearance too large
l
Faulty speed sensor
4. Then, in order to observe the output state of the wheel
speed sensors, shift into low gear vehicle) and drive
the wheels, observe the output voltage waveform of each
wheel speed sensor with an oscilloscope.
In the case of the FWD vehicle, observe the waveform with
an oscilloscope; for the front wheels, shift into low gear and
drive the wheels; for the rear wheels, turn the wheels
manually at a constant speed.
NOTE
1.
Waveform may also be observed by actually driving the
vehicle.
2. The output voltage is low when the wheel speed is low
and increases as the wheel speed increases.
TSB Revision