Mitsubishi L200. Manual — part 468

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-128

Inspection Procedure 7: The ASTC system cannot be disabled when ASC OFF switch is pressed to
turn the system OFF.

ASC Switch Circuit

ASC OFF
SWITCH

COMBINATION
METER

ILLUMINATION
CONTROL CIRCUIT

TAIL LAMP
RELAY

ETACS-ECU

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple

ASTC-ECU

NOTE

: RHD
:

NOTE

: RHD
: LHD

COMBINATION
METER

19

14

13

1

3

15

2

16

4

18

6

17

5

7

22

10

21

20

8 9

23

11

24

12

ACB00858

AC800980

AG

Connector: A-48

(B)

AC600688

Connector: C-13 <LHD>

BS

AC600687CR

Connectors: C-54, C-137, C-138 <LHD>

C-54

C-54

2

1

3

13

12

14

21

10

5

4

6

16

15

17

7 8 9

19

18

20

11

22

C-137, C-138

C-137, C-138

AC600623DK

Connector: C-13, C-14, C-137, C-138 <RHD>

C-13

C-14

C-14

C-13

2

1

3

13

12

14

21

10

5

4

6

16

15

17

7 8 9

19

18

20

11

22

C-137, C-138

C-137, C-138

AC600687CS

Connector: C-113, C-140 <LHD>

C-113 Harness side

18

19

21

22

20

2423

11

12

10 9

7

8

6

1413

171615

3

4

5

1

2

C-140 Harness side

1

5

6

4 3 2

AC600623

C-113

C-140

CX

Connectors: C-113, C-140 <RHD>

C-113

Harness side

C-140 Harness side

1

5

6

4 3 2

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-129

OPERATION
ASTC-ECU terminal No.29 is earthed every time the
ASC OFF switch is pressed. ASTC-ECU monitors
this operation state and turns the ASC and ATC sys-
tem ON or OFF.

COMMENT
The cause is probably an open-circuit in the ASC
OFF switch circuit.

PROBABLE CAUSES

• Malfunction of the ASC OFF switch

• Damaged harness, connector

• Malfunction of the hydraulic unit assembly (inte-

grated with ASTC-ECU)

DIAGNOSIS PROCEDURE

STEP 1. Connector check: A-48 ASTC-ECU
connector, C-13 intermediate connector, C-14
intermediate connector <RHD>, C-54
intermediate connector <LHD>, C-113
combination meter connector, C-137 joint
connector, C-138 joint connector, C-140 ASC OFF
switch connector

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Repair or replace it. Then go to Step 7.

STEP 2. Check the ASC OFF switch.
Refer to

P.35C-139

.

Q: Is the check result normal?

YES :

Go to Step 3.

NO :

Replace the ASC OFF switch (Refer to

P.35C-139

.). Then go to Step 7.

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-130

STEP 3. Check for open circuit in the wiring
harness between A-48 ASTC-ECU connector and
C-140 ASC OFF switch connector.
Check for open circuit in the wiring harness between
A-48 ASTC-ECU connector terminal No.29 and C-
140 ASC OFF switch connector terminal No.1.

Q: Is the check result normal?

YES :

Go to Step 4.

NO :

Repair the wiring harness between the A-48
ASTC-ECU terminal No.29 and the C-140
ASC OFF switch connector terminal No.1.
Then go to Step 7.

STEP 4. Voltage measurement at A-48 ASTC-ECU
connector.
(1) Disconnect the A-48 ASTC-ECU connector.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between the A-48 ASTC-

ECU connector terminal No.29.

OK:

• When the ASC OFF switch is not

pressed: System voltage

• When the ASC OFF switch is pressed:

1 V or less

Q: Is the check result normal?

YES :

Go to Step 5.

NO :

Go to Step 6.

STEP 5. Check for open circuit in the wiring
harness between C-140 ASC OFF switch
connector and the body earth.
Check for open circuit in the wiring harness between
C-140 ASC OFF switch connector terminal No.2 and
the body earth.

Q: Is the check result normal?

YES :

Go to Step 6.

NO :

Repair the wiring harness between the C-
140 ASC OFF switch connector terminal
No.2 and the body earth. Then go to Step 7.

STEP 6. Retest the system

Q: Does ASC system cancelled, when the ASC OFF

switch is push on?
YES :

It can be assumed that this malfunction is

intermittent. (Refer to GROUP 00, How to
Use Troubleshooting/Inspection Service
Points

− How to Cope with Intermittent

Malfunction ).

NO :

Replace the hydraulic unit (integrated with
ASTC-ECU) (Refer to

P.35C-140

.). Then go

to Step 7.

STEP 7. Retest the system

Q: Does ASC system cancelled, when the ASC OFF

switch is push on?
YES :

The procedure is complete.

NO :

Return to Step 1.

Inspection Procedure 8: ASTC System dose not operate.

COMMENT
The fail-safe function is probably cancelling ASTC
system. In this case, M.U.T.-III can be used to Retest
each system by checking the diagnosis codes.

PROBABLE CAUSES

• Malfunction of the CAN bus line.

• Malfunction of the ASTC-ECU.

• Battery voltage low.

DIAGNOSIS

STEP 1. Hydraulic unit check
Refer to

P.35C-135

.

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Connect the brake pipes correctly, repair the
external brake lines, or replace the hydraulic
unit.

STEP 2. Verify that the condition described by
the customer exists.

Q: Can any faults be found with the brake operation?

YES :

Check the brake system related

components except the ASTC system.

NO :

The procedure is complete.

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-131

Inspection procedure 9: The initial check sound of hydraulic unit is loud.

CAUTION

When installing brake tube, match the axial

centre of flare nut and brake tube with the centre
of hole at the hydraulic unit side, and check that
the fluid does not leak.
COMMENT ON TROUBLE SYMPTOM
The operation sound may be decreased by reducing
the load at the rubber mount portion of the brake
tube and hydraulic unit.

PROBABLE CAUSES

• Improper installation of the hydraulic unit

• Improper installation of the brake tube

DIAGNOSIS PROCEDURE

DRIVING CHECK
(1) Turn the ignition switch from the "LOCK" (OFF)

position to the "ON" position.

(2) When vehicle speed reaches 10 km/h, check the

operating sound volume and compare it with that
of the same model.

OK: The operating sound is the same vol-
ume or less by comparing with that of the
same model.

Q: Is the check result normal?

YES :

This diagnosis is complete.

NO :

Carry out adjustment for hydraulic unit
installation. (Refer to

P.35C-135

).

DATA LIST REFERENCE TABLE

M1355001500700

The following items can be read by the M.U.T.-III
from the ASTC-ECU input data.
When the system is normal.

Item No.

Check item

Check condition

Normal condition

01

FL wheel speed sensor

Perform a test run of the vehicle Speedometer display and

M.U.T.-III display almost agree
with each other.

02

FR wheel speed sensor

03

RL wheel speed sensor

04

RR wheel speed sensor

05

Power supply voltage

Always

System voltage

08

Lateral G sensor

Vehicle is stopped (on a level
surface)

0 m/s

2

Vehicle is running

-14.7

− 14.7 m/s

2

09

G-sensor

Vehicle is stopped (on a level
surface)

0 m/s

2

Vehicle is running

-14.7

− 14.7 m/s

2

10

Master cylinder pressure

-10

− 30 MPa

11

Steering angle

-900

− 900 deg

12

Yaw rate sensor

-130

− 130 deg/s

13

Stop lamp switch

The brake pedal is depressed

ON

The brake pedal is released

OFF

28

TCL off switch

TCL off switch: ON

ON

TCL off switch: OFF

OFF

40

Under Cranking

Engine cranking

YES

Not engine cranking

NO

57

Lateral G sensor without Cal.

-20 to 20 m/s

2