Mitsubishi Galant. Manual — part 527

SPECIAL TOOLS

TSB Revision

ANTI-LOCK BRAKING SYSTEM(ABS)

35B-41

SPECIA L TO O LS

M1352000600051

O N -VEH IC LE SERVIC E

BLEEDING

M1352001500046

CAUTION

Use the specified brake fluid. Avoid using a mixture of the
specified brake fluid and other fluid.

Specified brake fluid:
Conforming to DOT 3 or DOT 4

MASTER CYLINDER BLEEDING

Refer to GROUP 35A

−

On-vehicle Service

−

Bleeding

P.35A-

21

.

TOOL

TOOL NUMBER AND
NAME

SUPERSESSION

APPLICATION

MB991502 Scan tool

MB991496-OD

For checking of ABS
(Diagnostic trouble code
display when using the
scan tool)

MB991529
Diagnostic trouble code
check harness

Tool not necessary if scan
tool (MUT-II) is available.

For checking of ABS
(Diagnostic trouble code
display when using the
ABS warning light)

MB991223
Harness set
A:MB991219
Inspection harness

MB991223
MB991709-01

Wheel speed sensor
output voltage
measurement

B991502

MB991529

MB991223

A

AH

ON-VEHICLE SERVICE

TSB Revision

ANTI-LOCK BRAKING SYSTEM(ABS)

35B-42

BRAKE LINE BLEEDING

CAUTION

For vehicles with ABS, be sure to filter/strain the brake
fluid being added to the master cylinder reservoir tank.
Debris may damage the hydraulic unit.
Refer to GROUP 35A

−

On-vehicle Service

−

Bleeding

P.35A-

21

.

WHEEL SPEED SENSOR OUTPUT VOLTAGE
MEASUREMENT

M1352001600054

Required Special Tool:

•

MB991219: Inspection Harness

1. Lift up the vehicle and release the parking brake.

2. Disconnect the ABS-ECU connector, and then use special

tool MB991219 to measure the output voltage at the
harness side connector.

3. Manually turn the wheel to be measured 1/2 to 1 turn/

second. Measure the output voltage with a voltmeter or
oscilloscope.

Output voltage:

••••

When measured with voltmeter: 42 mV or more

••••

When measured with oscilloscope (maximum
voltage): 120 mV or more

Probable causes of low output voltage

••••

Wheel speed sensor pole piece-to-ABS rotor
clearance too large

••••

Faulty wheel speed sensor

TERMINAL NO.

Front left

Rear right

Front right

Front right

123

1

9

5

2

22

20

6

AC004008

ABS-ECU CONNECTOR
(HARNESS SIDE)

AB

ON-VEHICLE SERVICE

TSB Revision

ANTI-LOCK BRAKING SYSTEM(ABS)

35B-43

NOTE: Check the connection of the sensor harness and
connector before using the oscilloscope.

4. To observe the waveform with an oscilloscope:

•

Front Wheels: Shift into low gear and drive the wheels.

•

Rear Wheels: Turn the wheels manually at a constant
speed

NOTE: The output waveform is low when the wheel speed is
low. Similarly, it will be higher as the wheel speed increases.
Waveform may also be observed by driving the vehicle.

POINTS IN WAVEFORM MEASUREMENT

NOTE: The wheel speed sensor cable moves in relation to motion of the front or rear suspension. Therefore,
it is likely that it has an open circuit only when driving on rough roads but it functions normally when driving on
smooth roads. It is recommended to observe sensor output voltage waveform also under special conditions,
such as driving on a rough road.

HYDRAULIC UNIT CHECK

M1352001700051

Required Special Tool:

•

MB991502: Scan Tool (MUT-II)

AC000949 AB

WHEN TURNED MANUALLY

IN LOW GEAR, IDLING
[5

−

6 km/h (3

−

4 mph)]

[10.0 ms/DIV 1 V/DIV]

[10.0 ms/DIV 1 V/DIV]

SYMPTOM

PROBABLE CAUSES

REMEDY

Too small or zero waveform ampli-
tude

Faulty wheel speed sensor

Replace sensor

Incorrect pole piece-to-ABS rotor
clearance

Adjust clearance

Waveform amplitude fluctuates ex-
cessively (This is no problem if the
minimum amplitude is 100 mV or
more)

Axle hub eccentric or with large
runout

Replace hub

Noisy or disturbed waveform

Open circuit in wheel speed sensor Replace sensor

Open circuit in harness

Repair harness

Incorrectly mounted wheel speed
sensor

Mount correctly

ABS rotor with missing or dam-
aged teeth

Replace ABS rotor

ON-VEHICLE SERVICE

TSB Revision

ANTI-LOCK BRAKING SYSTEM(ABS)

35B-44

CAUTION

•

The roller of the braking force tester and the tire should
be dry during testing.

•

When testing the front brakes, apply the parking brake.
When testing the rear brakes, stop the front wheels
with chocks.

1. Jack up the vehicle. Then support the vehicle with rigid

racks at the specified jack-up points or place the front or rear
wheels on the rollers of the braking force tester.

2. Release the parking brake, and feel the drag force (drag

torque) on each road wheel. When using the braking force
tester, take a reading of the brake drag force.

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOOK" (OFF) position.
3. Turn the ignition switch to the "LOCK" (OFF) position and

set scan tool MB1502 as shown in the illustration.

4. After checking that the shift lever <M/T> or the selector lever

<A/T> is in neutral, start the engine.

5. Use scan tool MB991502 to force-drive the actuator.

NOTE: The ABS system will switch to the scan tool mode
and the ABS warning light will illuminate.

NOTE: When the ABS has been interrupted by the fail-safe
function, scan tool MB991502 actuator testing cannot be
used.

6. Turn the wheel by hand and check the change in braking

force when the brake pedal is depressed. When using the
braking force tester, depress the brake pedal until the
braking force is at the following values, and check that the
braking force changes to the brake drag force ins

AC003081 AB

16 PIN

MB991502

Front wheel

785

−

981 N (176

−

220 lb)

Rear wheel

588

−

784 N (132

−

176 lb)

AC000954AB

SCAN TOOL ACTUATOR TEST
(ITEM NO.01, 02, 03, 04) START

1 s

2 s

3 s

DEPRESSED

RELEASED

PRESSURE INCREASE

PRESSURE DECREASE

PRESSURE HOLD

LOCK

DRAG FORCE
WHEN THE
PEDAL IS FREE

PEDAL
OPERATION

SOLENOID
VALVE
POSITION

CHECKING
THE BRAKE
FORCE