Mitsubishi Evolution X. Manual — part 814

ON-VEHICLE SERVICE

TSB Revision

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-263

ON-VEHICLE SERVICE

HYDRAULIC UNIT CHECK

M1355006100138

Required Special Tools:

• MB991958: M.U.T.-III Sub Assembly

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A (Vehicles with

CAN communication system)

1. Raise the vehicle using a jack and support the specified

points with a rigid rack.

CAUTION

Before connecting or disconnecting scan tool, always turn
the ignition switch to the LOCK (OFF) position.
2. Before setting scan tool, turn the ignition key to the LOCK

(OFF) position.

3. With the M/T vehicles, check that the shift lever is in the

neutral position. With the TC-SST vehicle, check that the
selector lever is in the "N" position. Then, start the engine of
the vehicle.

MB991223

a. MB991219
b. MB991220
c. MB991221
d. MB991222

Harness set

a. Test harness
b. LED harness
c. LED harness

adaptor

d. Probe

General service tools Continuity check and voltage

measurement at harness wire or
connector for loose, corroded or
damaged terminals, or terminals
pushed back in the connector.

a. Connector pin contact

pressure inspection

b. Power circuit inspection
c. Power circuit inspection
d. Commercial tester connection

MB992006
Extra fine probe

−

Continuity check and voltage
measurement at harness wire or
connector for loose, corroded or
damaged terminals, or terminals
pushed back in the connector.

Tool

Tool number and
name

Supersession

Application

MB991223

a

d

c

b

DO NOT USE

BA

MB992006

ON-VEHICLE SERVICE

TSB Revision

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-264

4. When carrying out the actuator tests No. 01 to 04, perform

the actuator tests using scan tool while depressing the brake
pedal. When carrying out the actuator tests No.05 to 08,
perform the actuator tests using scan tool without
depressing the brake pedal. When carrying out the actuator
tests, rotate the wheel by hands to confirm that the braking
force changes.
NOTE:

.

•

While performing the actuator test, the ABS warning light
flashes at a rate of 2 Hz.

•

When ASC-ECU is disabled due to the fail-safe function,
the M.U.T.-III actuator test cannot be performed.

•

After the actuator test has been performed, the ABS
warning light, brake warning light, ASC warning display,
and ASC OFF indicator light illuminate until the ignition
switch is turned to ON again or the communication
between scan tool and ASC-ECU is terminated.

5. This is indicated as shown in the above.

AC400780AE

M.U.T.-III actuator test
(No.01, 02, 03, 04) start

M.U.T.-III actuator test
(No.05, 06, 07, 08) start

M.U.T.-III actuator test
(No.01, 02, 03, 04)

M.U.T.-III actuator test
(No.05, 06, 07, 08)

M.U.T.-III actuator test
(No.05, 06, 07, 08)

M.U.T.-III actuator test
(No.01, 02, 03, 04)

Pedal operation

Depressed

Released

Solenoid valve position
(ABS)

Increase in pressure

Steady pressure

Reduction in pressure

Increase in pressure

Steady pressure

Reduction in pressure

Solenoid valve position
(TCL)

Checking the brake force

Checking the brake force

Lock

When the pedal is free

Those with a braking effort

Approx.
1 seconds

Approx.
1 seconds

Approx.
2 seconds

Approx.
2 seconds

Approx.
3 seconds

Approx.
3 seconds

Those without a braking effort

ON-VEHICLE SERVICE

TSB Revision

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-265

6. When any malfunction has been found, take a necessary

action according to the "Judgment Table."

Judgment Table

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

(OFF) position, and then disconnect scan tool.

Display on
scan tool

Operation

Inspection
result

Judgme
nt

Probable cause

Remedy

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
vehicle.

• Select the vehicle

to be inspected
using scan tool,
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 scan tool,
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.

ON-VEHICLE SERVICE

TSB Revision

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-266

IN THE EVENT OF A DISCHARGED BATTERY

M1355006200146

WARNING

If the ASC is not operating, the vehicle will be unsta-
ble during braking, Do not drive the vehicle with the
ASC-ECU connector disconnected or with the ASC
not operating.

If the engine is started using a booster cable when the battery
is completely flat, and the vehicle is then driven without waiting
for the battery to be recharged, the engine may misfire and it
may not be possible to drive the vehicle. This is because the
ASC consumes a large amount of current when carrying out its
initial checks. If this happens, recharge the battery fully.

G AND YAW RATE SENSOR CALIBRATION

M1355009300142

CAUTION

Prior to calibration, check that no G and yaw rate sen-
sor-related diagnostic trouble codes are set.

CAUTION

After the following procedure is complete, carry out cali-
bration to let the ASC-ECU learn the neutral position of the
G and yaw rate sensor.

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

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

CAUTION

Before connecting or disconnecting the scan tool, turn the
ignition switch to the "LOCK" (OFF) position.
3. Set the scan tool with the ignition "LOCK" (OFF).
4. Turn the ignition switch to the ON position.
5. Select the relevant system from the menu.
6. Select "ABS/ASC/ASTC/WSS" from the system lists in

"System select", and press "OK" button.

7. Select "Special function" in "ABS/ASC/ASTC/WSS".
8. Select "Sensor calibration" in "Special function".
9. Select "G sensor calibration" from the selected item, and

press "OK" button.

10.The screen displays "G sensor calibration: The selected

command will be executed. Are you sure? Caution: Please
check the execution conditions." Then press "OK" button.

11."Execute: The command was executed." will be shown.

Then press "OK" button.

12.Select "Lateral/G sensor calibration" from the selected item,

and press "OK" button.

13.The screen displays "Lateral/G sensor calibration: The

selected command will be executed. Are you sure? Caution:
Please check execution conditions." Then press "OK"
button.