Mitsubishi Galant (2004+). Manual - part 329

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-507

STEP 1. Use scan tool MB991958 to select "ECU COMM 
Check" on the SWS monitor display.

Check the column-ECU.

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. Connect 
special tool MB991910 before connecting special tool 
MB991812. Be sure to connect special tool MB991806 after 
turning on special tool MB991824.
(1) Connect the special tool. Refer to "How to connect SWS 

monitor 

P.54B-13

."

(2) Turn the ignition switch to the "ON" position.
(3) Operate the scan tool according to the procedure below to 

display "ECU COMM Check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "ECU COMM Check."

(4) Scan tool (MUT-III) should show "OK" on the "ECU COMM 

Check" menu for the "COLUMN ECU" menu.

Q: Is "OK" displayed for the "COLUMN ECU" menu?

YES : Go to Step 2.
NO :  Refer to Inspection Procedure A-2 "Communication 

with the column switch (column-ECU) is not possible 

P.54B-72

."

AC305411AB

MB991910

DATA LINK

CONNECTOR

MB991827

MB991824

MB991806

MB991812

AC302210

COLUMN SWITCH 
CONNECTOR

COLUMN SWITCH 
CONNECTOR AT 
HARNESS SIDE 

MB991812

AB

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-508

STEP 2. Check the turn-signal light and lighting switch.

Remove the turn-signal light and the lighting switch. Then 
check continuity between the switch terminals.

Q: Are the turn-signal light and lighting switch in good 

condition?
YES : Go to Step 3.
NO :  Replace the turn-signal light and the lighting switch. 

The input signal from the column switch (turn-signal 
light and lighting switch) should be able to be checked 
and the functions described in the "CIRCUIT 
OPERATION" should work normally.

STEP 3. Replace the column switch.
(1) Replace the column switch.
(2) The input signal from the column switch (turn-signal light 

and lighting switch) should be able to be checked and the 
functions described in the "CIRCUIT OPERATION" should 
work normally.

Q: Is the input signal from the column switch (turn-signal 

light and lighting switch) input normally?
YES : No action is necessary and testing is complete.
NO :  Replace the ETACS-ECU. The input signal from the 

column switch (turn-signal light and lighting switch) 
should be able to be checked and the functions 
described in the "CIRCUIT OPERATION" should work 
normally.

SWITCH 
POSITION

TESTER 
CONNECTION

SPECIFIED 
CONDITION

OFF

1 

− 2, 2 − 3, 2 − 11, 

2 

− 12, 5 − 9, 7 − 9

Open circuit

Taillight switch

5 

− 9

Less than 2 ohms

Headlight switch

5 

− 9, 7 − 9

Less than 2 ohms

Passing switch

2 

− 12

Less than 2 ohms

Dimmer switch

2 

− 11, 2 − 12

Less than 2 ohms

Turn-signal light 
switch (LH)

1 

− 2

Less than 2 ohms

Turn-signal light 
switch (RH)

2 

− 3

Less than 2 ohms

AC003177

UPPER SIDE

AB

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-509

INSPECTION PROCEDURE M-6: Column switch: ETACS-ECU does not receive any signal from the 
windshield mist wiper switch, the windshield intermittent wiper switch, the windshield low-speed 
wiper switch, the windshield high-speed wiper switch or the windshield washer switch.

NOTE: This troubleshooting procedure requires the 
use of scan tool MB991958 and SWS monitor kit 
MB991813. For details on how to use the SWS mon-
itor, refer to "How to use SWS monitor 

P.54B-15

."

.

CIRCUIT OPERATION
The ETACS-ECU operates the windshield wiper and 
washer according to signal from the windshield wiper 
and washer switch.

.

TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the windshield wiper and 
washer do not work normally.

.

TROUBLESHOOTING HINTS

• The column switch may be defective (windshield 

wiper and washer switch)

• The ETACS-ECU may be defective

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

• MB991813: SWS Monitor Kit

• MB991806: SWS Monitor Cartridge

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

• MB991822: Probe Harness

AC004263

Windshield Wiper and Windshield Washer Switch Input Circuit

INPUT SIGNAL PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-510

STEP 1. Use scan tool MB991958 to select "ECU COMM 
Check" on the SWS monitor display.

Check the column-ECU.

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. Connect 
special tool MB991910 before connecting special tool 
MB991812. Be sure to connect special tool MB991806 after 
turning on special tool MB991824.
(1) Connect the special tool. Refer to "How to connect SWS 

monitor 

P.54B-13

."

(2) Turn the ignition switch to the "ON" position.
(3) Operate the scan tool according to the procedure below to 

display "ECU COMM Check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "ECU COMM Check."

(4) Scan tool (MUT-III) should show "OK" on the "ECU COMM 

Check" menu for the "COLUMN ECU" menu.

Q: Is "OK" displayed for the "COLUMN ECU" menu?

YES : Go to Step 2.
NO :  Refer to Inspection Procedure A-2 "Communication 

with the column switch (column-ECU) is not possible 

P.54B-72

."

AC305411AB

MB991910

DATA LINK

CONNECTOR

MB991827

MB991824

MB991806

MB991812

AC302210

COLUMN SWITCH 
CONNECTOR

COLUMN SWITCH 
CONNECTOR AT 
HARNESS SIDE 

MB991812

AB