Mitsubishi Montero (2004+). Manual - part 1067

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-111

INSPECTION PROCEDURE 5: The ABS Warning Light Flashes Twice after the Ignition Switch is 
Turned to the "On" Position. The Light Illuminates When the Ignition Switch is Turned to the "Start" 
Position, and When the Ignition Switch is Returned to the "On" Position, it Flashes Once.

AC204875AB

ABS Warning Light Circuit

AC204674

AB

B-21X (VALVE RELAY)

CONNECTOR: B-21X

AC204547AC

CONNECTORS: D-208, D-210

D-208

D-210

JUNCTION BLOCK
(FRONT VIEW)

AC204546 AB

CONNECTOR: D-03

D-03 (GR)

AC203901AF

CONNECTOR: E-120

E-120

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-112

.

CIRCUIT OPERATION

• The ABS warning light power is supplied from the 

ignition switch. The M-ASTC-ECU grounds the 
circuit to illuminate the light. The light also illumi-
nates when the valve relay is switched to OFF.

• The M-ASTC-ECU illuminates the ABS warning 

light for three seconds while running self-check. 
This light can be illuminated for three seconds 
upon start-up or ignition switch to the "ON" posi-
tion, engine stopped. The M-ASTC-ECU drives 
the valve relay in the order of OFF to ON to OFF 
to ON during initial check to check the valve relay.

.

TECHNICAL DESCRIPTION (COMMENT)
The M-ASTC-ECU causes the ABS warning light to 
illuminate during the initial check (three seconds). 
During the initial check, the valve relay turns from off 
to on, off and back to on again, and if there is a open 
circuit in the harness between the M-ASTC-ECU and 
the ABS warning light, the light will illuminate only 
when the valve relay is OFF because of a valve relay 
test, etc.

.

TROUBLESHOOTING HINTS

• Damaged wiring harness or connector

• Malfunction of the M-ASTC-ECU

.

DIAGNOSIS

Required Special Tool:

• MB991223: Harness Set

AC204385

CONNECTORS: E-108, E-110

AE

E-110

E-108(B)

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-113

STEP 1. Check the ABS warning light circuit at 
M-ASTC-ECU connector E-120.
(1) Remove the valve relay.

(2) Disconnect M-ASTC-ECU connector E-120 and measure at 

the harness side.

(3) Ground the terminal 62.
(4) Turn the ignition switch to the "ON" position. The ABS 

warning light should turn on.

Q: Is the ABS warning light turn on?

YES : Replace the M-ASTC-ECU. Then go to Step 3.
NO :  Go to Step 2.

AC204674

AC

VALVE RELAY

AC203901

AC204627

CONNECTOR: E-120

AS

E-120

HARNESS CONNECTOR:
COMPONENT SIDE

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-114

STEP 2. Check the harness wires between combination 
meter connector D-03 terminal 56 and M-ASTC-ECU 
connector E-120 terminal 62.
NOTE: After inspecting M-ASTC-ECU connector E-106, 
inspect the wire. If M-ASTC-ECU connector E-106 is damaged, 
repair or replace it. Refer to GROUP 00E, Harness Connector 
Inspection 

P.00E-2

.Then go to Step 3.

AC204690 AC

CONNECTOR: D-03

D-03 (GR)

HARNESS CONNECTOR: 
COMPONENT SIDE

D-03

AC203901

AC204627AG

CONNECTOR: E-120

E-120

HARNESS CONNECTOR: 
COMPONENT SIDE

E-120