Mitsubishi L200. Manual - part 438

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-8

NOTES WITH REGARD TO DIAGNOSIS

M1355009500061

1. The ASTC is a system which controls the brake 

pressure and engine power by means of the 
operation of the ECU. Accordingly, the following 
symptoms may occur at times, but these are a 
sign of normal ASTC operation, and do not 
indicate a malfunction.

Phenomenon

Explanation of phenomenon

When the engine starts, a knocking sound can be heard coming 
from the engine compartment.

This sound occurs as a result of system 
operation checking, and is not a 
malfunction.

Although the accelerator pedal is depressed, the engine speed 
does not increase or drops.

This occurs as a result of the ASC or ATC 
operation, and is not a malfunction.

• Sound of the motor inside the ABS hydraulic unit operation. 

(whine)

• When ASTC operates, sound is generated from the vehicle 

chassis due to repeated brake application and release. 
(Thump: suspension; squeak: tyres)

This is the sound of normal system 
operation, and is not a malfunction.

Shocks are felt if the brake pedal is depressed when driving at 
low speed.

This is due to system operation checking 
(starting-of check when the vehicle speed 
reaches a certain number of km/h) and is 
not a malfunction.

2. ASTC is system for assisting driver's operation. 

Accordingly, advise the customer to drive safely 
on such roads by lowering the vehicle speed and 
not being too overconfident.

3. Diagnosis detection condition can vary depending 

on the diagnosis code. Make sure that checking 
requirements listed in the "Comment" are satisfied 
when checking the trouble symptom again.

BRAKE WARNING LAMP, ABS WARNING 
LAMP, ASTC INDICATOR LAMP, ASTC 
OFF INDICATOR LAMP INSPECTION

M1353007000042

For the brake warning lamp and ABS warning lamp, 
refer to GROUP 35B 

− Brake Warning Lamp and 

ABS Warning Lamp Check .

AC509414 AD

Approximately 3 s

A, B
lamp

Ignition
switch

Illuminated

Not
illuminated

START

ON

ACC

A

ASTC OFF indicator lamp

A

:

ASTC indicator lamp

B

:

B

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-9

Check that the ASTC indicator lamp and ASTC OFF 
indicator lamp illuminates as follows.
1. When the ignition switch is turned to the "ON" 

position, the ASTC indicator lamp and ASTC OFF 
indicator lamp illuminates for approximately 3 
seconds and then switches off.

2. If the illumination is other than the above, check 

the diagnosis codes.

DIAGNOSIS FUNCTION

M1355001000835

ASTC-ECU has the following functions for easier 
system checks. The following items can be diag-
nosed using M.U.T-III.

• Diagnosis code set (Refer to ).

• Service data output (Refer to ).

• Actuator test (Refer to ).

CHECK OF FREEZE FRAME DATA

To detect fault and store the diagnosis code, the 
ASTC-ECU obtains data before the confirmation of 
the diagnosis code and data when the diagnosis 
code is confirmed, and then stores the current condi-
tion of the ASTC-ECU. By analysing each data from 
M.U.T.-III, the troubleshooting can be performed 
more efficiently. Display items of the freeze frame 
data are as follows.

Display item list

Item No.

Item name

Data item

Unit

02

Ignition cycle

Number of times the ignition switch is turned 
"ON" or "LOCK (Extinguished)" after the 
past failure transition.

Number of 
counts is 
displayed.

03

Elapsed time

Total elapsed time after a diagnosis code is 
generated

min

*

04

Accumulated minute

Cumulative time for current malfunction of 
diagnosis code

min

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-10

NOTE: 

*

: Total elapsed time can be stored up to 

65534 minutes. The display of M.U.T.-III is fixed to 
65534 minutes after 65534 minutes have elapsed. 
Or, if the battery is disconnected, the total elapsed 
time cannot be measured properly. Thus, 65535 min-
utes (null value) is displayed. Since the value is cal-
culated according to the information from the ASTC-
ECU, a proper value may not be displayed when the 
ASTC-ECU time-out has occurred.

FAIL-SAFE FUNCTION

If any malfunction is detected by the self-diagnostic 
function, ASTC-ECU Illuminates the ABS warning 
lamp, brake warning lamp

*

, ASTC indicator lamp and 

ASTC OFF indicator lamp, and it disables ABS, EBD 
and ASTC control.
NOTE: *: The brake warning lamp and display are 
used as EBD control warning lamp.

Illumination condition of warning lamp in case of failure

Diagno
sis 
code 
No.

Item

ABS warning 
lamp

Brake warning 
lamp

ASTC indicator 
lamp

ASTC OFF 
indicator lamp 

C1200

Wheel speed 
sensor (FR) (signal 
open circuit)

Illuminated

Extinguished

*1

Illuminated

*2

Illuminated

Illuminated

C1205

Wheel speed 
sensor (FL) (signal 
open circuit)

C1210

Wheel speed 
sensor (RR) (signal 
open circuit)

Extinguished

*3

Illuminated

*2

C1215

Wheel speed 
sensor (RL) (signal 
open circuit)

C1201

Wheel speed 
sensor (FR) (signal 
short circuit)

Illuminated

Extinguished

*1

Illuminated

*2

Illuminated

Illuminated

C1206

Wheel speed 
sensor (FL) (signal 
short circuit)

C1211

Wheel speed 
sensor (RR) (signal 
short circuit)

Extinguished

*3

Illuminated

*2

C1216

Wheel speed 
sensor (RL) (signal 
short circuit)

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-11

C1202

Wheel speed 
sensor (FR) 
(malfunction power 
circuit)

Illuminated

Extinguished

*1

Illuminated

*2

Illuminated

Illuminated

C1207

Wheel speed 
sensor (FL) 
(malfunction power 
circuit)

C1212

Wheel speed 
sensor (RR) 
(malfunction power 
circuit)

Extinguished

*3

Illuminated

*2

C1217

Wheel speed 
sensor (RL) 
(malfunction power 
circuit)

C1223

G and yaw rate 
sensor (active 
check error)

Illuminated

Extinguished

Illuminated

Illuminated

C1225

*4

Wheel speed 
sensor malfunction 
(abnormality in tyre 
size)

Illuminated

Extinguished

Illuminated

Illuminated

Diagno
sis 
code 
No.

Item

ABS warning 
lamp

Brake warning 
lamp

ASTC indicator 
lamp

ASTC OFF 
indicator lamp