Mitsubishi Galant 9G. Manual — part 108

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-428

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CIRCUIT OPERATION

The ETACS-ECU operates the dome light according
to the following signals:

• Ignition switch (IG1): ON or OFF

• Key reminder switch: ON or OFF

• Door switches: ON or OFF

• Trunk lid latch assembly: ON or OFF

• Driver’s door lock actuator switch: LOCK or

UNLOCK

.

TECHNICAL DESCRIPTION (COMMENT)

Is the dome light does not flash normally, a
burned-out dome light bulb, the input circuits from
the switches described in "CIRCUIT OPERATION",
the power supply line to the switches or the
ETACS-ECU may be defective.

.

TROUBLESHOOTING HINTS

• The front dome light bulb may be defective

• The rear dome light bulb may be defective

• The trunk light bulb may be defective

• 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

AC305231BA

CONNECTOR: C-28

AC305415AL

CONNECTOR: C-204

JUNCTION BLOCK

(FRONT VIEW)

AC207121

CONNECTORS : C-218, C-219

C-218(GR)

C-219

AG

JUNCTION BLOCK

(REAR VIEW)

AC400530

CONNECTORS: D-02, D-03, D-37 D-02

D-03

AF

D-37

AC400532

AD

CONNECTORS: D-07, D-10

D-07

D-10

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-429

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

STEP 1. Check which of the front dome light, rear dome
light or trunk light do not illuminate normally.
Q: Which of the front dome light, rear dome light or trunk

light fail to illuminate normally?
Front dome light and rear dome light : Go to Step 2.
Front dome light : Go to Step 4.
Rear dome light : Go to Step 9.
Trunk light : Go to Step 14.

STEP 2. Check map light assembly connector D-02
<without sunroof>, overhead console assembly connector
D-03 <with sunroof> and ETACS-ECU connector C-219 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is map light assembly connector D-02 <without

sunroof>, overhead console assembly connector D-03
<with sunroof> and ETACS-ECU connector C-219 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

. Check that the front dome light and rear

dome light illuminates normally.

AC305413 AG

CONNECTOR: C-219

JUNCTION BLOCK SIDE

JUNCTION BLOCK

(REAR VIEW)

AC400530

CONNECTORS: D-02, D-03

D-02
D-03

AE

D-02

D-03

HARNESS SIDE

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-430

STEP 3. Check the wiring harness between map light
assembly connector D-02 (terminals 1 and 2) <without
sunroof> or overhead console assembly connector D-03
(terminals 1 and 2) <with sunroof> and ETACS-ECU
connector C-219 (terminals 6 and 5).
Q: Is the wiring harness between map light assembly

connector D-02 (terminals 1 and 2) <without sunroof> or
overhead console assembly connector D-03 (terminals
1 and 2) <with sunroof> and ETACS-ECU connector
C-219 (terminals 6 and 5) in good condition?
YES : No action is necessary and testing is complete.
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. Check that
the front dome light and rear dome light illuminates
normally.

STEP 4. Check map light assembly connector D-02
<without sunroof> or overhead console assembly
connector D-03 <with sunroof> for loose, corroded or
damaged terminals, or terminals pushed back in the
connector.
Q: Is map light assembly connector D-02 <without

sunroof> or overhead console assembly connector
D-03 <with sunroof> in good condition?
YES : Go to Step 5.
NO : Repair or replace the damaged component(s). Refer

to GROUP 00E, Harness Connector Inspection

P.00E-2

. Check that the front dome light illuminates

normally.

STEP 5. Check the front dome light bulb.
Q: Is the front dome light bulb in good condition?

YES : Go to Step 6.
NO : Replace the front dome light bulb. Check that the front

dome light illuminates normally.

AC305413 AG

CONNECTOR: C-219

JUNCTION BLOCK SIDE

JUNCTION BLOCK

(REAR VIEW)

AC400530

CONNECTORS: D-02, D-03

D-02
D-03

AE

D-02

D-03

HARNESS SIDE

AC400530

CONNECTORS: D-02, D-03

D-02
D-03

AE

D-02

D-03

HARNESS SIDE

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-431

STEP 6. Check the ground circuit to the front dome light.
Measure the resistance at map light assembly connector
D-02 <without sunroof> or overhead console assembly
connector D-03 <with sunroof>.
(1) Disconnect map light assembly connector D-02 <without

sunroof> or overhead console assembly connector D-03
<with sunroof> and measure the resistance available at the
wiring harness side of the connector.

(2) Measure the resistance value between terminal 3 and

ground.

• The resistance should be 2 ohms or less.

Q: Is the measured resistance 2 ohms or less?

YES : Go to Step 8.
NO : Go to Step 7.

STEP 7. Check the wiring harness between map light
assembly connector D-02 (terminal 3) <without sunroof>
or overhead console assembly connector D-03 (terminal 3)
<with sunroof> and ground.
Q: Is the wiring harness between map light assembly

connector D-02 (terminal 3) <without sunroof> or
overhead console assembly connector D-03 (terminal 3)
<with sunroof> and ground in good condition?
YES : Replace the overhead console assembly. Check that

the front dome light illuminates normally.

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. Check that
the front dome light illuminates normally.

AC400530

CONNECTORS: D-02, D-03

D-02
D-03

AE

D-02

D-03

HARNESS SIDE

AC209364 HA

CONNECTOR D-02
(HARNESS SIDE)

AC209364HB

CONNECTOR D-03
(HARNESS SIDE)

AC400530

CONNECTORS: D-02, D-03

D-02
D-03

AE

D-02

D-03

HARNESS SIDE