Mitsubishi Outlander (2003+). Manual — part 279

ON-VEHICLE SERVICE

ANTI-SKID BRAKING SYSTEM (ABS)

35B-59

ON-VEHICLE SERVICE

ABS SENSOR OUTPUT VOLTAGE
MEASUREMENT

M1352001600485

Lift up the vehicle and release the parking brake.

1. Disconnect the ABS-ECU connector, and

measure the output voltage at the harness side
connector.

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

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

Terminal No.

Output voltage:
42 mV or higher when measured using a
multimeter
120 mVP-P or higher when measured using a
oscilloscope

3. If the output voltage is lower than that given

above, the cause may be the following, so check
or replace the ABS sensor if necessary.

•

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

•

Faulty ABS sensor

WAVE PATTERN INSPECTION USING AN
OSCILLOSCOPE
After checking the connection of the ABS sensor
harness and the connector, take a reading of the
output voltage wave patterns for each ABS sensor
using an oscilloscope as follows.
Start the engine, the transmission shift lever to 1st
gear, and then spin the wheel.
NOTE:

.

•

You can also take a reading of the wave pattern
by actually driving the vehicle in this condition.

•

The output voltage will be lower when the wheel
speed is lower, and will become higher as the
wheel speed becomes higher.

Front left

Front right

Rear left

Rear right

16

9

27

11

26

10

28

17

AC201294

AH

25

8

15

16

17

27

28

26

11

9

10

12

13

14

23

24

22 21

7

6

5

4

20

19

3

2

18

1

Harness connector

AC000949 AF

When turned by hand

When idling (5

−

6 km/h), with 1st gear

[10.0 ms/DIV IV/DIV]

ON-VEHICLE SERVICE

ANTI-SKID BRAKING SYSTEM (ABS)

35B-60

POINTS IN WAVEFORM MEASUREMENT

NOTE: The ABS 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.

Symptom

Probable causes

Remedy

Too small or zero waveform
amplitude

Faulty ABS sensor or excessive
gap between it and the ABS rotor

Replace ABS sensor

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

Axle hub eccentric or with large
runout

Replace hub assembly

Faulty ABS-ECU earth

Repair harness wires

Noisy or disturbed waveform

Open circuit in ABS sensor

Replace ABS sensor

Open circuit in harness

Repair harness wire

Incorrectly mounted ABS sensor

Mount ABS sensor correctly

ABS rotor with missing or
damaged teeth

Replace ABS rotor

ON-VEHICLE SERVICE

ANTI-SKID BRAKING SYSTEM (ABS)

35B-61

HYDRAULIC UNIT CHECK

M1352001700620

CAUTION

•

The roller of the braking force tester and the
tyre 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 MUT-II/III, always turn the
ignition switch to the "LOOK" (OFF) position
before connecting or disconnecting the MUT-II/III.

3. Turn the ignition switch to the "LOCK" (OFF)

position and set the MUT-II/III as shown in the
illustration.

4. After checking that the shift lever is in neutral,

start the engine.

5. Use the MUT-II/III to force-drive the actuator.

NOTE: The ABS system will switch to the
MUT-II/III mode and the ABS warning lamp will
illuminate.
NOTE: When the ABS has been interrupted by
the fail-safe function, the MUT-II/III actuator
testing cannot be used.

AC300830

Steering shaft

MUT-II

AC

<Using the MUT-II>

AC308915 AC

MB991911

16-PIN

MB991827

MB991824

<Using the MUT-III>

ON-VEHICLE SERVICE

ANTI-SKID BRAKING SYSTEM (ABS)

35B-62

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 inspected in step
2 when the actuator is force-driven. The result
should be as shown in the diagram above.

7. If the result of inspection is abnormal, repair

according to the Diagnosis Table below.

8. After inspection, disconnect the MUT-II/III

immediately after turning the ignition switch to the
"LOCK" (OFF) position.

AC000954AH

MUT-II/III actuator test
(Item No.01, 02, 03, 04) start

1 seconds

2 seconds

3 seconds

Depressed

Released

Increase in pressure

Reduction in pressure

Steady pressure

Lock

Drag force when the
pedal is free

Pedal
operation

Solenoid
valve
position

Checking
the brake
force

Approx. 0.05 seconds

Front wheel

785

−

981 N

Rear wheel

588

−

784 N

Diagnosis Table

MUT-II/III
Display

Operation

Inspection result

Judgme
nt

Probable cause

Remedy

01 FR VALBE
02 FL VALBE
03 RR VALBE
04 RL VALBE

•

Depress brake pedal
to lock wheel.

•

Using the MUT-II/III,
select the wheel to be
checked and force the
actuator to operate.

•

Turn the selected
wheel manually to
check the change of
brake force.

Brake force is
released for
three seconds
after wheels
have been
locked.

Normal

−

−

Wheel does not
lock when brake
pedal is
depressed.

Abnor
mal

Clogged brake
line other than
hydraulic unit

Check and clean
brake line

Clogged
hydraulic circuit
in hydraulic unit

Replace
hydraulic unit
assembly

Brake force is
not released

Incorrect
hydraulic unit
brake tube
connection

Connect correctly

Hydraulic unit
solenoid valve
not functioning
correctly

Replace
hydraulic unit
assembly