Mitsubishi Galant (2004+). Manual - part 334

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-527

INSPECTION PROCEDURE N-3: ETACS-ECU does not receive any signal from any of the door 
switches.

JUNCTION BLOCK

ETACS-
ECU

JUNCTION BLOCK SIDE

REAR DOOR 
SWITCH (RH)

FRONT DOOR 
SWITCH (RH)

FRONT DOOR 
SWITCH (LH)

REAR DOOR 
SWITCH (LH)

Door Switches Input Circuit

AC305233

CONNECTOR: C-13

AR

AC305415AL

CONNECTOR: C-204

JUNCTION BLOCK

(FRONT VIEW)

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-528

.

CIRCUIT OPERATION
The ETACS-ECU operates the following functions or 
systems according to signal from the front or rear 
door switches:

• Ignition key reminder tone alarm function <front 

door switch (LH)>

• Light reminder tone alarm function <front door 

switch (LH)>

• Door ajar warning buzzer <all door switches>

• Ignition key reminder tone alarm <front door 

switches>

• Power window timer function <front door 

switches>

• Sunroof timer function <front door switch (LH)>

• Headlight automatic shutdown function <front 

door switch (LH)>

• Keyless entry system <all door switches>

• Timer lock <all door switches>

• Dome light <all door switches>

• Interior light automatic-shutdown function <all 

door switches>

• Ignition key hole illumination light <front door 

switch (LH)>

• Door-ajar indicator light <all door switches>

.

TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the functions or systems 
described in "CIRCUIT OPERATION" do not work 
normally. If the signal is not normal, the front or rear 
door switches or the ETACS-ECU may be defective.

.

TROUBLESHOOTING HINTS

• The front or rear door switches may be defective

• The wiring harness or connectors may have 

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

• The ETACS-ECU may be defective

AC305413

C-219

C-217

CONNECTORS: C-217, C-219

AF

JUNCTION BLOCK

(REAR VIEW)

AC305268

AN

CONNECTORS: D-06, D-16

D-16

D-06

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-529

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

• MB991910: MUT-III Main Harness A

STEP 1. Check the input signal (by using the pulse check 
mode of the monitor).

Check the input signals from the all door switches.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect the scan tool MB991958. Refer to "How to connect 

SWS monitor 

P.54B-13

."

(2) Operate scan tool MB991958 according to the procedure 

below to display "Pulse check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "Pulse Checking."

(3) Check that scan tool MB991958 sounds.
Q: When the front and rear doors are opened/closed, does 

the scan tool MB991958 sound?
When the front doors are opened and closed, scan tool 
MB991958 does not sound. : Refer to Inspection 

Procedure M-4 "ETACS-ECU does not receive any 
signal from the front door switches 

P.54B-497

."

When the rear door (LH) is opened and closed, scan tool 
MB991958 does not sound. : Go to Step 2.
When the rear door (RH) is opened and closed, scan 
tool MB991958 does not sound. : Go to Step 7.

STEP 2. Check rear door switch (LH) connector D-16 for 
loose, corroded or damaged terminals, or terminals 
pushed back in the connector.

Q: Is rear door switch (LH) connector D-16 in good 

condition?
YES : Go to Step 3.
NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

. If the functions described in "CIRCUIT 

OPERATION" work normally, the input signal from the 
rear door switch (LH) should be normal.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305268

AH

CONNECTOR: D-16

HARNESS SIDE

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-530

STEP 3. Check the rear door switch (LH).

Remove the rear door switch (LH). Refer to GROUP 42, Door, 
Door Assembly 

P.42-37

. Then check continuity between the 

switch terminals and the body ground.

Q: Is the rear door switch (LH) in good condition?

YES : Go to Step 4.
NO :  Replace the rear door switch (LH). If the functions 

described in "CIRCUIT OPERATION" work normally, 
the input signal from the rear door switch (LH) should 
be normal.

STEP 4. Measure resistance at the lower metal part of the 
rear door switch (LH) in order to check the ground circuit 
to the rear door switch (LH).
NOTE: Check that the rear door switch (LH) is grounded to the 
vehicle body via its mounting screw.
Remove the cap, and measure the resistance value between 
the lower metal part and ground.

• The resistance should be 2 ohms or less.

Q: Is the measured resistance 2 ohms or less?

YES : Go to Step 5.
NO :  Check the installation of the switch, and repair if 

necessary. If the functions described in "CIRCUIT 
OPERATION" work normally, the input signal from the 
rear door switch (LH) should be normal.

STEP 5. Check ETACS-ECU connector C-219 for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.

Q: Is ETACS-ECU connector C-219 in good condition?

YES : Go to Step 6.
NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

. If the functions described in "CIRCUIT 

OPERATION" work normally, the input signal from the 
rear door switch (LH) should be normal.

SWITCH 
POSITION

TESTER 
CONNECTION

SPECIFIED 
CONDITION

Released (ON)

1 

− body ground

Less than 2 ohms

Pressed (OFF)

1 

− body ground

Open circuit

1 2 3

ACX01865 AC

ON

OFF

AC210276AB

METAL PART

CUP

AC305413 AG

CONNECTOR: C-219

JUNCTION BLOCK SIDE

JUNCTION BLOCK

(REAR VIEW)