Mitsubishi Galant (2004+). Manual - part 317

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-459

STEP 4. Check the input signal by using "DATA LIST" 
menu of the SWS monitor.

Check the input signals from the following switches:

• Ignition switch: OFF

• Driver’s or front passenger’s door: open

(1) Operate scan tool MB991958 according to the procedure 

below to display "ETACS ECU."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Data List."
f. Select "ETACS ECU."

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

described in the table below.

Q: Does the scan tool MB991958 display "IG SW (IG1)" as 

normal condition?
YES : Go to Step 5.
NO :  Refer to Inspection Procedure M-2 "ETACS-ECU 

does not receive any signal from the ignition switch 
(IG1) 

P.54B-490

."

ITEM NO.

ITEM NAME

NORMAL CONDITION

ITEM 30

IG SW (IG1)

OFF

AC305411AB

MB991910

DATA LINK

CONNECTOR

MB991827

MB991824

MB991806

MB991812

AC302210

COLUMN SWITCH 
CONNECTOR

COLUMN SWITCH 
CONNECTOR AT 
HARNESS SIDE 

MB991812

AB

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-460

STEP 5. Check the input signal (by using the pulse check 
mode of the monitor).

Check the input signals from the following switches:

• Key reminder switch

• Door switches

• Trunk lid latch assembly

(1) 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."

(2) Check if scan tool MB991958 sounds or not.

Q: When the key reminder switch, any door switch, or the 

trunk lid is operated, does scan tool MB991958 sound?
Buzzer of scan tool MB991958 sounds normally. : 

Replace the ETACS-ECU. Verify that the dome light 
dimming function works normally.

Scan tool MB991958 does not sound when the ignition 
key is removed and reinserted : Refer to Inspection 

Procedure N-1 "ETACS-ECU does not receive a 
signal from the key reminder switch 

P.54B-518

."

Scan tool MB991958 does not sound whenever a door 
switch is operated : Refer to Inspection Procedure N-3 

"ETACS-ECU does not receive any signal from any of 
the door switches 

P.54B-527

."

When the trunk lid is opened and closed, scan tool 
MB991958 does not sound. : Refer to Inspection 

Procedure N-7 "ETACS-ECU does not receive any 
signal from trunk lid latch assembly 

P.54B-560

."

ITEM NAME

CONDITION

key reminder switch

Remove and reinsert the ignition 
key

door switches

Open or close one of the doors

trunk lid latch assembly

Open or close the trunk lid

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-461

INSPECTION PROCEDURE K-4: Interior Light: The ignition key hole illumination light does not 
illuminate or go out normally.

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

."

BATTERY

RELAY
BOX

KEY REMINDER
SWITCH

IGNITION
KEY HOLE
ILLUMINATION
LIGHT

· FRONT DOOR SWITCH
· IGNITION SWITCH (IG1)
· KEY REMINDER SWITCH

ETACS-
ECU

JOINT 
CONNECTOR (1)

Ignition Key Hole Illumination Light Circuit

AC305231

C-01

C-29

CONNECTORS: C-01, C-29

BI

AC305413AL

CONNECTOR: C-218

C-218 (GR)

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-462

.

CIRCUIT OPERATION

• When the driver's door is opened with the ignition 

switch at "ACC" position, the ETACS-ECU illumi-
nates the ignition key hole illumination light.

• The ignition key hole illumination light goes out in 

30 seconds after the driver's door is closed. The 
ignition key hole illumination light remains illumi-
nated for 30 seconds after the ignition key is 
pulled out.

• The ETACS-ECU operates the ignition key hole 

illumination light according to the input signals 
from the following switches:

• Ignition switch (IG1): OFF

• Key reminder switch: OFF

• Interior light loaded signal: ON

• Vehicle condition:

• Ignition switch: "LOCK" (OFF) or "ACC" posi-

tion

• Ignition key: Removed from the ignition key 

cylinder

• Driver’s door: Opened or closed

.

TECHNICAL DESCRIPTION (COMMENT)
If the ignition key hole illumination light does not illu-
minate, the input circuits from the switches described 
in "CIRCUIT OPERATION", the key reminder switch 
(ignition key hole illumination light bulb) or the 
ETACS-ECU may be defective.

.

TROUBLESHOOTING HINTS

• Trouble in input signal system

• 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

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

AC305235

CONNECTOR: C-310

AD