Mitsubishi Montero (2004+). Manual - part 1120

M-ASTC DIAGNOSIS

TSB Revision

MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-191

.

CIRCUIT OPERATION
The Active skid control system operation indicator 
light/Active traction control system operation indica-
tor light is connected from the ignition switch (IG1) 
through multi-purpose fuse No.6 and the combina-
tion meter to the M-ASTC-ECU. The M-ASTC-ECU 
turns on and off the indicator light.

.

TECHNICAL DESCRIPTION (COMMENT)
This symptom is caused by a shorted or opened 
Active skid control system operation indicator 
light/Active traction control system operation indica-
tor light circuit.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this condition:)

• Damaged wiring harness

• Burned-out bulb

• Melted fuse

• Malfunction of M-ASTC-ECU

.

DIAGNOSIS

Required Special Tool:

• MB991223: Harness Set

AC203901AG

CONNECTOR: E-121

E-121

AC204548

E-122

AO

CONNECTOR: E-122

M-ASTC DIAGNOSIS

TSB Revision

MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-192

STEP 1. Check the Active skid control system operation 
indicator light/Active traction control system operation 
indicator light circuit at M-ASTC-ECU connector E-121.

(1) Disconnect M-ASTC-ECU connector E-121 and measure at 

the harness side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal 74 and ground. It 

should be approximately 12 volts (battery positive voltage).

Q: Is the voltage approximately 12 volts (battery positive 

voltage)?
YES : Replace the M-ASTC-ECU and then go to Step 4.
NO :  Go to Step 2.

AC203901

AC204627AR

CONNECTOR: E-121

E-121

E-121

HARNESS CONNECTOR: 
COMPONENT SIDE

AC205144AB

CONNECTOR: E-121

HARNESS CONNECTOR: 
COMPONENT SIDE

M-ASTC DIAGNOSIS

TSB Revision

MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-193

STEP 2. Check the harness wires between ignition switch 
(IG1) connector D-204 terminal 2 and combination meter 
connector D-03 terminal 62.
NOTE: After inspecting combination meter connector D-03, 
ignition switch (IG1) connector D-204, junction block connector 
D-208 and D-210, inspect the wire. If combination meter con-
nector D-03, ignition switch (IG1) connector D-204, junction 
block connector D-208 and D-210 are damaged, repair or 
replace them. Refer to GROUP 00E, Harness Connector 
Inspection 

P.00E-2

. Then go to Step 4.

Q: Is the harness wire between ignition switch (IG1) 

connector D-204 terminal 2 and combination meter 
connector D-03 terminal 62 damaged?
YES : Repair the wiring harness wires between ignition 

switch (IG1) connector D-204 terminal 2 and 
combination meter connector D-03 terminal 62. Then 
go to Step 4.

NO :  Go to Step 3.

AC204687AD

CONNECTOR: D-03

D-03 (GR)

HARNESS CONNECTOR: 
COMPONENT SIDE

AC204709

CONNECTOR: D-204

D-204

AD

2
5

6

3

4

1

HARNESS CONNECTOR:

COMPONENT SIDE

AC204624 AG

CONNECTORS: D-208, D-210

D-208

JUNCTION BLOCK
(FRONT VIEW)

JUNCTION BLOCK CONNECTOR

D-208

D-210

D-210

1 2 3

4

12

9

8

7

6

10

5

13

11

JUNCTION BLOCK CONNECTOR

M-ASTC DIAGNOSIS

TSB Revision

MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-194

STEP 3. Check the harness wires between combination 
meter connector D-03 terminal 62 and M-ASTC-ECU 
connector E-121 terminal 74.
NOTE: After inspecting combination meter connector combina-
tion meter connector D-03, intermediate connector E-122 and 
M-ASTC-ECU connector E-121, inspect the wire. If combina-
tion meter connector D-03, intermediate connector E-122 and 
M-ASTC-ECU connector E-121 are damaged, repair or replace 
them. Refer to GROUP 00E, Harness Connector Inspection 

P.00E-2

. Then go to Step 4.

Q: Is the harness wire between combination meter 

connector D-03 terminal 62 and M-ASTC-ECU connector 
E-121 terminal 74 damaged?
YES : Repair it and then go to Step 4.
NO :  Replace the combination meter (printed circuit board), 

and then go to Step 4.

AC204687AD

CONNECTOR: D-03

D-03 (GR)

HARNESS CONNECTOR: 
COMPONENT SIDE

AC203901

AC204627AR

CONNECTOR: E-121

E-121

E-121

HARNESS CONNECTOR: 
COMPONENT SIDE

AC204548

E-122(L)

AP

CONNECTOR: E-122

2

1

3

13

12

14

21

10

5

4

6

16

15

17

7 8 9

19

18

20

11

22