Mitsubishi Colt Ralliart. Manual - part 642

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-113

Operation pattern of items 01 to 08 

CHECK AT ECU TERMINALS

M1357001400011

TERMINAL VOLTAGE CHECK

1. Operate the lock lever to disconnect the 

ASC-ECU harness connector as shown in the 
figure.

2. Connect the ABS check harness (Special tool: 

MB991984) to measure the voltages between 
each check connector terminal and earth terminal 
(No. 43 or 46).

NOTE: When the ignition switch is turned to "ON," 
ASC-ECU performs the initial check for approx. 3 
seconds. Do not measure the terminal voltage 
during that period.

3. Terminal layout is shown in the figure.

AC400776

Complete

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

1s

2s

Approx. 0.05s

Approx. 0.01s

Solenoid valve
(ABS)

AC

Hold

Pressure decrease

Pressure increase

Cut valve
Suction valve
(TCL/Stability 
 control)

Complete

MUT-III actuator test
(Item No.05, 06, 07, 08)
start

Pump motor

Drives

Stops

Pressure increase

Hold

Pressure decrease

AC601007AB

A-05: ASC-ECU connector

AC601121AB

MB991984

Check connector

ASC-ECU

ASC-ECU harness connector

Main

Index

Group

TOC

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-114

Terminal 
No.

Check items

Check conditions

Normal condition

6

Stop lamp switch input

Brake switch: OFF (Release the brake pedal.)

Approximately 0 V

Brake switch: ON (Depress the brake pedal.)

System voltage

8

Wheel speed sensor (RR) 
input

Ignition switch: ON

0.4 to 1.3 V

10

Wheel speed sensor (RL) 
input

Ignition switch: ON

0.4 to 1.3 V

11

Wheel speed sensor (RL) 
power supply

Ignition switch: ON

Voltage that is 
approx. 0.7 V lower 
than the ASC-ECU 
power supply 
voltage

13

Wheel speed sensor (FL) 
input

Ignition switch: ON

0.4 to 1.3 V

23

Brake switch input

Brake switch: ON (Release the brake pedal.)

Approx. 0 V

Brake switch: OFF (Depress the brake pedal.)

System voltage

27

Parking brake switch input Parking brake switch: ON

System voltage

Parking brake switch: OFF

Approx. 0 V

28

Wheel speed sensor (FR) 
input

Ignition switch: ON

0.4 to 1.3 V

29

Wheel speed sensor (FR) 
power supply

Ignition switch: ON

Voltage that is 
approx. 0.7 V lower 
than the ASC-ECU 
power supply 
voltage

30

Wheel speed sensor (RR) 
power supply

Ignition switch: ON

Voltage that is 
approx. 0.7 V lower 
than the ASC-ECU 
power supply 
voltage

32

Brake fluid level switch 
input

Brake fluid level switch: ON

Approx. 0 V

Brake fluid level switch: OFF

System voltage

34

Wheel speed sensor (FL) 
power supply

Ignition switch: ON

Voltage that is 
approx. 0.7 V lower 
than the ASC-ECU 
power supply 
voltage

40

ASC-ECU power supply

Ignition switch: ON

System voltage

43

ASC-ECU earth, solenoid 
valve earth

Always

0 V

44

Solenoid valve power 
supply (fusible link No. 5)

Always

System voltage

45

Motor power supply 
(fusible link No. 3)

Always

System voltage

46

Motor earth

Always

0 V

Main

Index

Group

TOC

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-115

CONTINUITY CHECK AT WIRING 
HARNESS-SIDE CONNECTOR

1. Disconnect the A-05 connector, and connect the 

ABS check harness (Special tool: MB991984) to 
the harness-side connector.
NOTE: Do not connect the ABS check harness 
(Special tool: MB991984) to the ASC-ECU.

2. Check the continuity between terminals shown in 

the chart below.

3. Terminal layout is shown in the figure.

AC601085AE

MB991984

ASC-ECU

Check connector

ASC-ECU harness connector

Connector terminal number

Signal

Normal condition

43 

− body earth

Earth

Continuity exists (2 

Ω or less)

46 

− body earth

Earth

Continuity exists (2 

Ω or less)

Main

Index

Group

TOC

ON-VEHICLE SERVICE

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-116

ON-VEHICLE SERVICE

HYDRAULIC UNIT (HU) CHECK

M1357001600015

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 shift lever is in the neutral 

position, and then start the engine.

4. Use the M.U.T.-III to perform the actuator test with 

depressing the brake pedal. When carrying out 
the actuator tests, rotate the wheel by hands to 
confirm that the braking force changes.
NOTE: During the actuator test, the brake warn-
ing lamp, ABS warning lamp and ASC indicator 
lamp illuminate and the ABS/ASC control is pro-
hibited
NOTE: When ASC-ECU is disabled due to the 
fail-safe function, the M.U.T.-III actuator test can-
not be performed.

Main

Index

Group

TOC