Mitsubishi Lancer (4A9 engine). Manual — part 82

ON-VEHICLE SERVICE

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-181

Judgment Table

Display on
M.U.T.-III

Operation

Test result

Judgme
nt

Cause

Measure

01 FL wheel
ABS drive
02 FR wheel
ABS drive
03 RL wheel
ABS drive
04 RR wheel
ABS drive

• Depress the brake

pedal to lock the
wheel.

• Select the vehicle

to be inspected
using M.U.T.-III,
perform the
actuator test.

• Rotate the selected

wheel by hands to
confirm the braking
force.

Braking force
decreases for 3
seconds from
the lock status.

Normal

−

−

The wheel
does not lock
even if the
brake pedal is
depressed.

Error

Clogged brake line
other than hydraulic
unit

Check and
clean the brake
line.

Clogged hydraulic
circuit in the hydraulic
unit

Replace the
hydraulic unit
assembly.

Braking force
does not
decrease.

Faulty routing of
hydraulic unit brake
tube

Route the
brake tube
correctly.

Malfunction of
hydraulic unit solenoid
valve operation

Replace the
hydraulic unit
assembly.

05 FL wheel
TCL drive
06 FR wheel
TCL drive
07 RL wheel
TCL drive
08 RR wheel
TCL drive

• Select the vehicle

to be inspected
using M.U.T.-III,
perform the
actuator test.

• Rotate the selected

wheel by hands to
confirm the braking
force.

Lock condition
occurs for 3
seconds from
the status
without braking
force.

Normal

−

−

The wheel
does not lock.

Error

• Faulty routing of

hydraulic unit brake
tube

• Clogged brake line

other than hydraulic
unit

Check and
clean the brake
line.

Clogged hydraulic
circuit in the hydraulic
unit

Replace the
hydraulic unit
assembly.

7. After the inspection, turn the ignition switch to the

LOCK (OFF) position, and then disconnect
M.U.T.-III.

Hydraulic unit installation adjustment
Refer to

P.35C-185

.

1. Operate the pre-removal steps for the hydraulic

unit.

2. Remove all brake tubes.
3. Remove the protector.
4. Loosen the mounting bolt and nut of the hydraulic

unit bracket.

5. Install all brake tubes temporarily.

6. Shake hydraulic unit to all directions with both

hands to make the hydraulic unit bracket insulator
fit with the unit.

7. Install the the hydraulic unit bracket with mounting

bolt and nut not to load the brake tube.

8. Install the protector.
9. Install all brake tubes securely.

NOTE: Install the flare nut taking care not to let
the brake tube turn together.

10.Operate the post-installation steps of the

hydraulic unit.

ON-VEHICLE SERVICE

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-182

MEASURES FOR DISCHARGED
BATTERY

M1355006200102

CAUTION

Because the vehicle posture when applying the
brakes becomes unstable, do not leave ABS/ASC
disabled (for example, ASC-ECU connector dis-
connection).
When starting the engine using a booster cable with
the battery fully discharged, if you begin driving the
vehicle before the battery is fully charged, the engine
misfire may occur and you cannot start the vehicle.
This is because ABS/ASC consumes more electric
current to perform the self-check. In this case,
charge the battery fully.

ALL SENSOR CALIBRATION (G AND YAW
RATE SENSOR, STEERING WHEEL
SENSOR, BRAKE FLUID PRESSURE
SENSOR)

M1357003900012

CAUTION

Before carrying out the calibration, check that
the diagnosis code related to the steering wheel
sensor, G and yaw rate sensor, or brake fluid
pressure sensor is not set.

CAUTION

When the next operation has been completed,
carry out the calibration to make ASC-ECU learn
the neutral point of the steering wheel sensor, G
and yaw rate sensor, and brake fluid pressure
sensor.

• ASC-ECU replacement

CAUTION

Carry out the calibration under the following con-
ditions.

• The vehicle has one occupant (driver) only.
• Turn the steering wheel to set the wheels in

the straight-ahead positions.

• The brake pedal is not depressed. (The stop

lamp switch is OFF.)

1. Park the vehicle on a level surface.

CAUTION

Before connecting or disconnecting M.U.T.-III,
always turn the ignition switch to the LOCK
(OFF) position.
2. Before setting M.U.T.-III, turn the ignition key to

the LOCK (OFF) position.

3. Turn the ignition switch to the ON position.

4. Select "ABS/ASC/ASTC."
5. Select "Special function."
6. Select "Sensor calibration."
7. Select "all sensor calibration."
8. Before removing M.U.T.-III from the vehicle, turn

the ignition key to the LOCK (OFF) position.

G AND YAW RATE SENSOR
CALIBRATION

M1355009300313

CAUTION

Before performing calibration, check that the G
and yaw rate sensor-related diagnosis code is
not set.

CAUTION

After the next operation has been completed,
carry out the calibration to make ASC-ECU learn
the neutral point of the G and yaw rate sensor.

• G and yaw rate sensor replacement
• ASC-ECU replacement

Park the vehicle on a level surface.
1. Turn the ignition switch to the ON position.
2. Turn the ignition key to the LOCK (OFF) position.

CAUTION

Before connecting or disconnecting M.U.T.-III,
always turn the ignition switch to the LOCK
(OFF) position.
3. Check that the ignition key is in the LOCK (OFF)

position, and then set M.U.T.-III.

4. Turn the ignition switch to the ON position.
5. On the Menu, select "System selection."
6. On the "System selection," select "ABS/ASC/

ASTC/WSS" in the "System table," and then click
the "OK" button.

7. In the "ABS/ASC/ASTC/WSS" field, select

"Special function".

8. Among the selected items, select "Learn lateral G-

sensor neutral position" and then press the "OK"
button.

9. "Learn lateral G-sensor neutral position: Are you

sure to execute the selected item? Note: Check
the execution conditions." is displayed. Then,
press the "OK" button.

10."Execute command: Executed" is displayed.

Then, press the "OK" button.

11.The neutral point is learned.
12.Turn the ignition key to the LOCK (OFF) position,

and remove M.U.T.-III from the vehicle.

ON-VEHICLE SERVICE

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-183

STEERING WHEEL SENSOR
CALIBRATION

M1355009200338

CAUTION

After the next operation has been completed,
carry out the following two operations:

• Alignment adjustment <Front>
• Steering wheel sensor (column switch assem-

bly) replacement, removal, installation

• ASC-ECU replacement

1. Update the neutral position stored in the

steering wheel sensor.

2. Reset the calibrated value of the steering

angle stored in ASC-ECU.

CAUTION

• Before performing the calibration, check if the

steering wheel sensor-related diagnosis code
is set in ASC-ECU.

• When the diagnosis code other than C121A is

set, carry out the inspection according to
each troubleshooting procedure.

Park the vehicle on a level surface with tyres and

steering wheel positioned in a straight ahead
direction.

1. Turn the ignition switch to the ON position.
2. Turn the ignition key to the LOCK (OFF) position.

CAUTION

Before connecting or disconnecting M.U.T.-III,
always turn the ignition switch to the LOCK
(OFF) position.
3. Check that the ignition key is in the LOCK (OFF)

position, and then set M.U.T.-III.

4. Turn the ignition switch to the ON position.
5. On the Menu, select "System selection."
6. In "System table" of "System selection," select

"Steering angle sensor," and then press the "OK"
button.

7. In "Steering angle sensor," select "Special

function."

8. In "Special function," select "Learn neutral

position of steering angle sensor."
NOTE: When the neutral position of steering
angle sensor has been learned, "Neutral position
learned already: in order to relearn the neutral
position, press the OK button to initialise the
steering angle sensor neutral position." is dis-
played. If it is okay, press the "OK" button.

9. In "Learn neutral position of steering angle

sensor," "Initialise neutral position of steering
angle sensor" is selected, thus press the "OK"
button.
NOTE: When the neutral position of steering
angle sensor has been learned, "Initialise neutral
position of steering angle sensor: Do you want to
execute? Note: The diagnosis code will be
erased." is displayed. Then, press the "OK" but-
ton.

10."Initialise neutral position of steering angle

sensor: Completed" is displayed. Then, press the
"OK" button.

11.Press the "OK" button.
12."Learn neutral position of steering angle sensor:

Do you want to execute? Note: Execute after the
tyres and steering wheel are aligned in a straight
ahead direction." is displayed. Then, press the
"OK" button.

13."Learn neutral position of steering angle sensor:

Completed" is displayed. Then, press the "OK"
button.

14.After turning the ignition switch to LOCK (OFF)

position, turn it to the ON position again.

15.On the Menu, select "System selection."
16.On the "System selection," select "ABS/ASC/

ASTC/WSS" in the "System table," and then click
the "OK" button.

17. In the "ABS/ASC/ASTC/WSS" field, select

"Special function".

18.In the "Special function," select "Learn sensor

neutral position."

19.In "Learn sensor neutral position," select "Learn

neutral position of steering angle sensor," and
then press the "OK" button.

20."Learn neutral position of steering angle sensor:

Are you sure to execute the selected item? Note:
Check the execution conditions." is displayed.
Then, press the "OK" button.

21."Execute command: Executed" is displayed.

Then, press the "OK" button.

22.In the "ABS/ASC/ASTC/WSS" field, select "Self

diagnosis." If diagnosis code of "C2205 SAS
internal error (past failure)" is set, erase it.

23.The neutral point is learned.
24.Turn the ignition key to the LOCK (OFF) position,

and remove M.U.T.-III from the vehicle.

ASC OFF SWITCH

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-184

BRAKE FLUID PRESSURE SENSOR
CALIBRATION

M1355024100048

CAUTION

Before performing calibration, check that the
brake fluid pressure sensor-related diagnosis
code is not set.

CAUTION

After the next operation has been completed,
carry out the calibration to make ASC-ECU learn
the neutral position of the brake fluid pressure
sensor.

• When the troubleshooting for code No. C123A

is carried out

• Brake fluid pressure sensor replacement
• ASC-ECU replacement

CAUTION

Always perform the calibration with the brake
pedal released (stop lamp switch is turned off).
1. Park the vehicle on a level surface.

CAUTION

Before connecting or disconnecting M.U.T.-III,
always turn the ignition switch to the LOCK
(OFF) position.
2. Before setting M.U.T.-III, turn the ignition key to

the LOCK (OFF) position.

3. Turn the ignition switch to the ON position.
4. Select "ABS/ASC/ASTC."
5. Select "Special function."
6. Select "Sensor calibration."
7. Select "M/C pressure sensor calibration."
8. Before removing M.U.T.-III from the vehicle, turn

the ignition key to the LOCK (OFF) position.

ASC OFF SWITCH

REMOVAL AND INSTALLATION

M1355020100303

ACA01061 AB

3

1

2

Removal steps

1.

Instrument panel lower (Refer to
GROUP 52A, Instrument panel
lower ).

2.

ASC OFF switch <except AS&G>

3.

ASG OFF & ASC OFF switch
<AS&G>

Removal steps (Continued)