Mitsubishi Galant 9G. Manual — part 7

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-24

NOTE: When checking the input signals (off, tail,
low-beam or high-beam), turn the ignition switch to
the "ON" position in order to disable the headlight
automatic shutoff function. However, since the head-
light operation does not depend on the ignition switch
positions, the scan tool MB991958 (MUT-III Sub
Assembly) does not display the title "IGNITION
SWITCH".

For checking item "HEADLIGHT HI", the scan tool
MB991958 (MUT-III Sub Assembly) displays "OFF"
on the item No.2 "DIMMER SW" when the headlights
are at high-beam. Therefore, the scan tool
MB991958 (MUT-III Sub Assembly) should display
"ON" momentarily when the dimmer switch is oper-
ated.

HEADLIGHT
LO

Headlight switch

HEADLIGHT SW (COLUMN
ECU)

Passing light
switch

PASSING SW (COLUMN
ECU)

OFF

Ignition switch
(IG1)

IG SW (IG1) (ETACS ECU) ON or OFF

Headlight
automatic shutoff
function

H/L AUTO-CUT (ETACS
ECU)

OFF

Response by the
front-ECU

FRONT ECU ACK (FRONT
ECU)

NORMAL ACK

PASSING
LIGHT

Passing light
switch

PASSING SW (COLUMN
ECU)

Response by the
front-ECU

FRONT ECU ACK (FRONT
ECU)

NORMAL ACK or HI-BEAM
ACK

F.FOG LIGHT

Headlight switch

HEADLIGHT SW (COLUMN
ECU)

Front fog light
switch

F.FOG LIGHT (COLUMN
ECU)

Headlight
automatic shutoff
function

H/L AUTO-CUT (ETACS
ECU)

OFF

Ignition switch
(IG1)

IG SW (IG1) (ETACS ECU) ON or OFF

Response by the
front-ECU

FRONT ECU ACK (FRONT
ECU)

NORMAL ACK or HI-BEAM
ACK

TAIL LIGHT

Headlight switch

HEADLIGHT SW (COLUMN
ECU)

OFF

Tail light switch

TAILLIGHT SW (COLUMN
ECU)

Passing light
switch

PASSING SW (COLUMN
ECU)

OFF

Ignition switch
(IG1)

IG SW (IG1) (ETACS ECU) ON or OFF

Headlight
automatic shutoff
function

H/L AUTO-CUT (ETACS
ECU)

OFF

Response by the
front-ECU

FRONT ECU ACK (FRONT
ECU)

NORMAL ACK

ITEM

ITEM NO. INPUT SIGNAL

DISPLAY ON SCAN TOOL NORMAL CONDITION

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-25

TURN SIGNAL

BUZZER

NOTE: The headlight automatic shutoff function
operates approximately one second after the lighting
monitor tone alarm starts sounding, and then the
tone alarm ceases sounding.

ITEM

ITEM NO. INPUT SIGNAL

DISPLAY ON SCAN TOOL NORMAL CONDITION

TURN-SIG.LH

Turn-signal light
switch (RH)

T/S RH SW (COLUMN
ECU)

OFF

Turn-signal light
switch (LH)

T/S LH SW (COLUMN
ECU)

Ignition switch
(IG1)

IG SW (IG1) (ETACS ECU) ON

TURN-SIG.RH 10

Turn-signal light
switch (RH)

T/S RH SW (COLUMN
ECU)

Turn-signal light
switch (LH)

T/S LH SW (COLUMN
ECU)

OFF

Ignition switch
(IG1)

IG SW (IG1) (ETACS ECU) ON

ITEM

ITEM NO. INPUT SIGNAL

DISPLAY ON SCAN TOOL NORMAL CONDITION

KEY
REMND.ALM

Ignition switch
(IG1)

IG SW (IG1) (ETACS ECU)

OFF

Front door switch

FRONT DOOR SW (ETACS
ECU)

Tone alarm

BUZZER (ETACS ECU)

LGT
MONI.ALRM

Headlight switch

HEADLIGHT SW (COLUMN
ECU)

Either is ON

Tail light switch

TAILLIGHT SW (COLUMN
ECU)

Ignition switch
(IG1)

IG SW (IG1) (ETACS ECU)

OFF

Front door switch

FRONT DOOR SW (ETACS
ECU)

Headlight
automatic shutoff
function

H/L AUTO-CUT (ETACS
ECU)

OFF

Tone alarm

BUZZER (ETACS ECU)

OTHER
ALARM

Ignition switch
(IG1)

IG SW (IG1) (ETACS ECU)

Tone alarm

BUZZER (ETACS ECU)

SWS DIAGNOSIS

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-26

SUNROOF

PULSE CHECK

M1549015100562

1. The input signals (signals other than SWS

communication line signals), which are
compatible with the SWS monitor by using the
scan tool MB991958 (MUT-III Sub Assembly) or
voltmeter, can be confirmed by the Pulse Check.

2. Use the scan tool MB991958 (MUT-III Sub

Assembly) or voltmeter to check the following
input signals.
NOTE: If a problem is found in the Pulse Check,
refer to Input Signal Chart

P.54B-63

Switches and their conditions, which are applicable
for Pulse Check

ITEM

ITEM NO. INPUT SIGNAL

DISPLAY ON SCAN TOOL NORMAL CONDITION

SUNROOF
OPE.

Ignition switch
(IG1)

IG SW (IG1) (ETACS ECU) ON

Response by the
sunroof-ECU

S/R ECU ACK (SUNROOF
ECU)

INPUT CHECK (only
momentarily when switch is
operated)

INPUT SIGNAL

REQUIREMENTS FOR SOUNDING TONE
ALARM

Key reminder switch

When the ignition key is pulled out

Hazard warning light switch

When the switch is turned from off to on

Door switches

A door is opened when all the doors are
closed

Door lock key cylinder switch

When a door is locked or unlocked by a key
cylinder

Door lock actuators

Move the door lock knob from lock position
to unlock position or vice versa

Door lock switch (incorporated in the power window main
switch and front power window sub switch)

When a door is locked or unlocked by a door
lock switch

Keyless entry transmitter

When the switch is turned from off to on

Interior light loaded signal

Illuminates the interior lights

DIAGNOSTIC TROUBLE CODE CHART

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-27

DIAGNOSTIC TROUBLE CODE CHART

M1549000700461

DIAGNOSTIC TROUBLE CODE PROCEDURES

DTC 001: Trouble in SWS communication line or ETACS-ECU

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

CAUTION

If DTC 001 is set in the ETACS-ECU, always diag-
nose the CAN main bus line.

TROUBLE JUDGMENT

The ETACS-ECU communicates with the column
switch, the front-ECU and the sunroof-ECU through
the SWS communication line. If there is any trouble
in the SWS communication line and the
ETACS-ECU, DTC 001 will be set.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble

• The wiring harness wire or connectors may have

loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector, or the
ETACS-ECU may be defective.

Past trouble

• If DTC 001 is set as past trouble, carry out diag-

nosis with particular emphasis on wiring and con-
nector(s) in the SWS communication line. For
diagnosis procedures, refer to "How to cope with
past trouble" (Refer to GROUP 00, How to treat
past trouble

P.00-16

TROUBLESHOOTING HINTS

• The wiring harness or connectors may have

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

DIAGNOSTIC TROUBLE
CODE NO.

DESCRIPTION

REFERENCE
PAGE

001

Trouble in SWS communication line or ETACS-ECU

P.54B-27

002

Trouble in column switch