Mitsubishi Galant (2004+). Manual - part 327

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-499

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

Check the input signals from the front 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: Does scan tool MB991958 sound when each front door 

is opened and closed?
When the front door (LH) is opened and closed, scan 
tool MB991958 does not sound. : Go to Step 2.
When the front door (RH) is opened and closed, scan 
tool MB991958 does not sound. : Go to Step 7.
When either front door is opened and closed, scan tool 
MB991958 sounds.  : Replace the ETACS-ECU. If the 

functions described in "CIRCUIT OPERATION" work 
normally, the input signal from the front door switches 
should be normal.

STEP 2. Check front door switch (LH) connector D-22 for 
loose, corroded or damaged terminals, or terminals 
pushed back in the connector. 

Q: Is front door switch (LH) connector D-22 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 
front door switch (LH) should be normal.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305268

HARNESS SIDE

CONNECTOR: D-22

AI

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-500

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

Remove the front 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 front door switch (LH) in good condition?

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

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

STEP 4. Measure resistance at the lower metal part of the 
front door switch (LH) in order to check the ground circuit 
to the front door switch (LH).
NOTE: Check that the front 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 
front 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 
front 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)

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-501

STEP 6. Check the wiring harness between front door 
switch (LH) connector D-22 (terminal 1) and ETACS-ECU 
connector C-219 (terminal 10).

NOTE: Also check junction block connector C-204 for loose, 
corroded, or damaged terminals, or terminals pushed back in 
the connector. If junction block connector C-204 is damaged, 
repair or replace the damaged component(s) as described in 
GROUP 00E, Harness Connector Inspection 

P.00E-2

.

Q: Is the wiring harness between front door switch (LH) 

connector D-22 (terminal 1) and ETACS-ECU connector 
C-219 (terminal 10) in good condition?
YES : Replace the ETACS-ECU. If the functions described 

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

NO :  The wiring harness may be damaged or the 

connector(s) may have loose, corroded or damaged 
terminals, or terminals pushed back in the connector. 
Repair the wiring harness as necessary. If the 
functions described in "CIRCUIT OPERATION" work 
normally, the input signal from the front door switch 
(LH) should be normal.

AC305413 AG

CONNECTOR: C-219

JUNCTION BLOCK SIDE

JUNCTION BLOCK

(REAR VIEW)

AC305268

HARNESS SIDE

CONNECTOR: D-22

AI

AC305415AJ

CONNECTOR: C-204

HARNESS SIDE

JUNCTION BLOCK

(FRONT VIEW)

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-502

STEP 7. Check front door switch (RH) connector D-34 for 
loose, corroded or damaged terminals, or terminals 
pushed back in the connector. 

Q: Is front door switch (RH) connector D-34 in good 

condition?
YES : Go to Step 8.
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 
front door switch (RH) should be normal.

STEP 8. Check the front door switch (RH).

Remove the front door switch (RH). Refer to GROUP 42, Door, 
Door Assembly 

P.42-37

. Then check continuity between the 

switch terminals and the body ground.

Q: Is the front door switch (RH) in good condition?

YES : Go to Step 9.
NO :  Replace the front door switch (RH). If the functions 

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

STEP 9. Measure resistance at the lower metal part of the 
front door switch (RH) in order to check the ground circuit 
to the front door switch (RH).
NOTE: Check that the front door switch (RH) 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 10.
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 
front door switch (RH) should be normal.

AC305264

HARNESS SIDE

CONNECTOR: D-34

AJ

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