Mitsubishi Montero (2004+). Manual - part 804

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-473

General circuit diagram for the theft-alarm

BATTERY

RELAY BOX
(FUSE     )

13

12

RELAY BOX
(FUSE     )

RELAY BOX

HEADLIGHT (RH)

HEADLIGHT (LH)

FRONT-ECU

DATA LINK
CONNECTOR

DATA LINK
CONNECTOR

ETACS-
ECU

JUNCTION
BLOCK

TRANSMITTER

CONTROL
CIRCUIT 

      HORN
(HIGH) (ROW) 

THEFT-ALARM
HORN RELAY 

THEFT-
ALARM
HORN 

HORN
RELAY 

KEY 
REMINDER 
SWITCH

HOOD
SWITCH

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-474

IGNITION
SWITCH (IG1)

RELAY BOX
(FUSE     )

18

ETACS-
ECU

JUNCTION
BLOCK

FRONT DOOR 
SWITCH 

(RH)

REAR DOOR 
SWITCH 

(RH)

FRONT DOOR 
SWITCH 

(LH)

REAR DOOR 
SWITCH 

(LH)

BACK DOOR LOCK 
ACTUATOR

BACK DOOR
SWITCH

DOOR LOCK 
ACTUATOR (FRONT: RH)

DOOR LOCK 
ACTUATOR (FRONT: LH)

BACK DOOR LOCK KEY
KEY CYLINDER SWITCH

DOOR LOCK KEY
CYLINDER SWITCH (RH)

DOOR LOCK KEY
CYLINDER SWITCH (LH)

THEFT-ALARM
INDICATOR LIGHT

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-475

INSPECTION PROCEDURE N-1: Theft-alarm System: Theft-alarm system is not armed (theft-alarm 
indicator light does not illuminate). 

NOTE: This troubleshooting procedure requires the 
use of scan tool MB991958 and SWS monitor kit 
MB991862. For details on how to use the SWS mon-
itor, refer to "How to use SWS monitor 

P.54B-10

."

JOINT 
CONNECTOR (7)

THEFT-ALARM
INDICATOR
LIGHT

RELAY
BOX

FUSIBLE
LINK

1

ETACS-
ECU

· DRIVER'S DOOR LOCK
  ACTUATOR SWITCH
· FRONT DOOR SWITCH
· FRONT PASSENGER'S DOOR
  LOCK ACTUATOR SWITCH
· KEY REMINDER SWITCH

INPUT SIGNAL

Theft-alarm Indicator Light Drive Circuit

ACX02274

FUSIBLE LINK (1)

AE

BATTERY

AC204170

CONNECTORS : D-02, D-28, D-105

BJ

D-28

D-105(B)

D-02

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-476

.

CIRCUIT OPERATION

• When the ETACS-ECU receives a "LOCK" signal 

from the door lock actuator switch, it illuminates 
the security indicator light for approximately 18 
seconds, and then set the theft-alarm system.

• The ETACS-ECU sets the theft-alarm system 

according to the input signals from the following 
signals:

• Ignition key reminder switch: ON

• Driver's and front passenger's door switch: 

OFF

• Rear door switches: OFF

• Driver's, front passenger's and back door lock 

key cylinder switch: OFF

• Driver's, front passenger's, rear and back 

doors actuator switch: LOCK

• Hood switch: OFF

• Transmitter switch: LOCK

• Vehicle condition:

• Ignition key: Removed from the ignition key 

cylinder

• All doors: Closed

• Driver's, front passenger's and back door lock 

key cylinder: Not being operated

• Hood: Closed

• Transmitter: Turn to the "LOCK" position

.

TECHNICAL DESCRIPTION (COMMENT)
If the theft-alarm system is set normally, the input sig-
nal circuit, the "SECURITY" indicator light or the 
ETACS-ECU may be defective.

.

TROUBLESHOOTING HINTS

• The theft-alarm indicator light may be defective

• The ignition key reminder switch may be defec-

tive

• The driver's or front passenger's door switch may 

be defective

• The door switches may be defective

• The driver's, the front passenger's or the back 

door lock key cylinder switch may be defective

• The driver's, front passenger's, the rear or the 

back door lock actuator switch may be defective

• The hood switch may be defective

• The transmitter may be defective

• The ETACS-ECU may be defective

• The wiring harness or connectors may have 

loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B

• MB991813: SWS Monitor Kit

• MB991806: SWS Monitor Cartridge

• MB991812: SWS Monitor Harness (For Column-ECU)

• MB991822: Probe Harness

AC204174

CONNECTOR : D-224

D-224(B)

AG