Content .. 79 80 81 82 ..

Mitsubishi Lancer (4A9 engine). Manual - part 81

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-177

Operation pattern of items 01 to 08

AC400776

1second

2 seconds

Approx. 0.05
second

Approx. 0.01
second

End

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

End

Increase in pressure

Steady pressure

Reduction in pressure

Increase in pressure

Steady pressure

Reduction in pressure

Drive

Stop

Cut valve,
Suction valve
(TCL/ASC)

Solenoid valve
(ABS)

Pump motor

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

CHECK AT ECU TERMINALS

M1355001700737

TERMINAL VOLTAGE CHECK

ACB01448

Lock lever

<LHD>

<RHD>

1. Operate the lock lever to disconnect the ASC-

ECU harness connector as shown in the figure.

AC401192 AO

ASC-ECU

MB991997

Check harness

A-58 ASC-ECU
harness connector

2. Connect the special tool ASC check harness

(MB991997) to measure the voltage between
each check connector terminal and the earth
terminal (No. 16 or 47).

Terminal
No.

Check item

Check condition

Normal condition

Motor power supply

Ignition switch: ON (OFF)

Approximately
system voltage

ASC-ECU power supply

Ignition switch: ON

Approximately
system voltage

Ignition switch: OFF

Approximately
system voltage

Ignition switch signal for ASC-
ECU activation

Ignition switch: ON

Approximately
system voltage

Ignition switch: OFF

1V or less

G and yaw rate sensor power
supply

Ignition switch: ON

Approximately
system voltage

Solenoid valve power supply

Ignition switch: ON (OFF)

Approximately
system voltage

Wheel speed sensor (FR) power
supply

Ignition switch: ON

Approximately
system voltage

Wheel speed sensor (RL) power
supply

Ignition switch: ON

Approximately
system voltage

Wheel speed sensor (RR) power
supply

Ignition switch: ON

Approximately
system voltage

Wheel speed sensor (FL) power
supply

Ignition switch: ON

Approximately
system voltage

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-178

CONTINUITY CHECK AT WIRING HARNESS-SIDE
CONNECTOR

ACB01448

Lock lever

<LHD>

<RHD>

1. Operate the lock lever to disconnect the ASC-

ECU harness connector as shown in the figure.

AC400817 FA

ASC-ECU

MB991997

Check harness

A-58 ASC-ECU
harness connector

ON-VEHICLE SERVICE

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-179

2. When performing the continuity check, turn the

ignition switch to LOCK (OFF) position, connect
the special tool ASC check harness (MB991997)
as shown in the figure, and disconnect the ASC-
ECU connector.

3. Check the continuity between terminals shown in

the chart below.

4. Terminal layout is shown in the figure.

Terminal No.

Signal

Normal condition

− body earth

Earth

Continuity exists (2

Ω or

less)

− body earth

Earth

ON-VEHICLE SERVICE

WHEEL SPEED SENSOR OUTPUT
CURRENT MEASUREMENT

M1355027300029

Refer to GROUP 35B

− Wheel speed sensor output

current measurement .

HYDRAULIC UNIT (HU) CHECK

M1355006100202

1. Raise the vehicle using a jack and support the

specified points with a rigid rack.

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. Confirm that the selector lever is in the "N"

position, and then start the engine.

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

perform the actuator tests using M.U.T.-III while
depressing the brake pedal. When carrying out
the actuator tests No.05 to 08, perform the
actuator tests using M.U.T.-III 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 lamp 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 can-
not be performed.

•

After the actuator test has been performed,
the ABS warning lamp, brake waning lamp,
ASC ON indicator lamp, and ASC OFF indica-
tor lamp illuminate until the ignition switch is
turned to ON again or the communication
between M.U.T.-III and ASC-ECU is termi-
nated.

AC400780AB

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.01, 02, 03, 04)

Pedal operation

Depressed

Released

Solenoid valve position

Increase in pressure

Steady pressure

Reduction in pressure

Increase in pressure

Steady pressure

Reduction in pressure

Cut valve, suction valve
position

Checking the brake force

Lock

Drag force when the pedal is free

Approx.
1 second

Approx.
2 seconds

Approx.
3 seconds

Those with a braking effort

Those without a braking effort

ON-VEHICLE SERVICE

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-180

5. This is indicated as shown in the above.

6. When any malfunction has been found, take a

necessary action according to the "Judgment
Table."

Content .. 79 80 81 82 ..