Mitsubishi Galant (2004+). Manual - part 267

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-259

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

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

Check the input signals from the sunroof switch.

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 scan tool MB991958.Refer to "How to connect 

SWS monitor 

P.54B-13

."

(2) Operate the 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) When each function of the sunroof switch is operated 

(turned on), check that scan tool MB991958 sounds.

Q: Does scan tool MB991958 sound when the sunroof 

switch is operated?
YES : Replace the sunroof motor assembly. Check that the 

sunroof works at all positions normally.

NO :  Refer to Inspection Procedure M-8 "ETACS-ECU 

does not receive any signal from the up, open or 
close/down switch 

P.54B-515

."

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-260

INSPECTION PROCEDURE F-3: Sunroof: Sunroof Timer Function does not Work Normally.

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

P.54B-15

."

.

CIRCUIT OPERATION

• The sunroof timer function works according to the 

signals from the following switches:

• Ignition switch (IG1): OFF

• Front door switch: OFF

• Vehicle condition

• Ignition switch: LOCK position

• Front door: Closed

• When the driver’s door is opened and closed 

while the sunroof timer function is on, the sunroof 
operative duration will be changed.

.

TECHNICAL DESCRIPTION (COMMENT)
Is the sunroof timer function does not work normally, 
the input circuits from the switches described in 
"CIRCUIT OPERATION", the sunroof motor assem-
bly, the ETACS-ECU or the SWS communication line 
may be defective.

.

TROUBLESHOOTING HINTS

• The front door switch may be defective

• The sunroof motor assembly 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: Test 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

SUNROOF-ECU

SUNROOF MOTOR
ASSEMBLY

· 

FRONT DOOR

 SWITCH (LH)

· IGNITION SWITCH (IG1)
· SUNROOF ECU ACK

INPUT SIGNAL

Sunroof Timer  Function

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-261

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

Check the following ECUs:

• ETACS-ECU

• Sunroof-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 "LOCK" (OFF) position.
(3) Operate the scan tool MB991958 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 MB991958 should show "OK" on the "ECU 

COMM Check" menus for both the "ETACS ECU" and the 
"SUNROOF ECU" menus.

Q: Is "OK" displayed for both the "ETACS ECU" and 

"SUNROOF ECU" menus?
"OK" is displayed for all the items : Go to Step 2.
"NG" is displayed for the "ETACS ECU" menu : Refer to 

Inspection Procedure A-3 "Communication with the 
ETACS-ECU is not possible 

P.54B-79

."

"NG" is displayed for the "SUNROOF ECU" menu : 

Refer to Inspection Procedure A-5 "Communication 
with the sunroof-ECU is not possible 

P.54B-94

."

AC305411AB

MB991910

DATA LINK

CONNECTOR

MB991827

MB991824

MB991806

MB991812

AC302210

COLUMN SWITCH 
CONNECTOR

COLUMN SWITCH 
CONNECTOR AT 
HARNESS SIDE 

MB991812

AB

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-262

STEP 2. Check the input signal by using "FUNCTION 
DIAG." menu of the SWS monitor.

Observe how the input signal is changed when the ignition 
switch is turned from the ON position to the "LOCK" (OFF) 
position.
(1) Operate the MUT-III according to the procedure below to 

display "SUNROOF-OPE."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f. Select "SUNROOF."
g. Select "SUNROOF-OPE."

(2) Check that normal conditions are displayed for the items 

described in the table below.

Q: Does the MUT-III display the items "IG SW (IG1)" and 

"S/R ECU ACK" as normal condition?
Normal conditions displayed for all the items : Replace 

the sunroof motor assembly. Check that the sunroof 
timer function works normally.

Normal condition is not displayed for the "IG SW (IG1)" : 

Refer to Inspection Procedure M-2 "ETACS-ECU 
does not receive a signal from the ignition switch 
(IG1) 

P.54B-490

."

Normal condition is not displayed for the "S/R ECU 
ACK" : Replace the sunroof motor assembly. Check that the 

sunroof timer function works normally.

ITEM NO.

ITEM NAME

NORMAL 
CONDITION

ITEM 30

IG SW (IG1)

OFF

ITEM 72

S/R ECU ACK

NORMAL ACK

AC305411AB

MB991910

DATA LINK

CONNECTOR

MB991827

MB991824

MB991806

MB991812

AC302210

COLUMN SWITCH 
CONNECTOR

COLUMN SWITCH 
CONNECTOR AT 
HARNESS SIDE 

MB991812

AB