Mitsubishi Galant (2004+). Manual - part 277

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-299

STEP 9. Check the wiring harness between windshield 
washer motor connector A-29 (terminal 2) and front-ECU 
connector A-12X (terminal 31).

Q: Is the wiring harness between windshield washer motor 

connector A-29 (terminal 2) and front-ECU connector 
A-12X (terminal 31) 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. Verify that 
the windshield washer works normally.

AC305977

CONNCTOR: A-12X

AI

21

22

23

24

25

26

27

28

29

30

31

RELAY BOX SIDE

AC305206AK

CONNECTOR: A-29

HARNESS SIDE

CONTINUE

Continue

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-300

54B

HEADLIGHT AND TAILLIGHT

GENERAL DESCRIPTION CONCERNING HEADLIGHTS AND TAILLIGHTS

M1549021300112

The following ECUs affect the functions and control 
of the headlights and the taillights.

Taillights and headlights illumination

.

Taillights
If the column switch sends a taillight switch "ON" signal to the 
front-ECU, the front-ECU turns on its taillight relay, causing the 
taillights to illuminate.
NOTE: This description covers the taillights only. In actual driv-
ing, the taillights may be turned off due to the headlight auto-
matic shut-off function. For the details of the headlight 
automatic shut-off function, refer to .

.

FUNCTION

CONTROL ECU

Taillights

Front-ECU, column switch

Headlights

ETACS-ECU, front-ECU, column switch

High-beam indicator light

ETACS-ECU, column switch

Headlight automatic-shutoff function

ETACS-ECU, front-ECU, column switch

Dimmer automatic reset function

Front-ECU, column switch

AC106502

ON

OFF

ON

OFF

Taillight
switch

Taillight
relay

AB

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-301

Headlights

If the column switch sends a headlight switch "ON" 
signal to the front-ECU, the front-ECU turns on its 
headlight relay (LOW), causing the low-beam head-
lights to illuminate. If the dimmer switch is turned on 
while the headlight relay (LOW) is on, the front-ECU 
turns on the headlight relay (HIGH), causing the 
high-beam headlights to illuminate.

NOTE: This description covers the headlights only. In 
actual driving, the headlights may be turned off due 
to the headlight automatic shut-off function. For the 
details of the headlight automatic shut-off function, 
refer to .

High-beam indicator light
At the same time that the high-beams are illuminated, the 
ETACS-ECU sends a signal to illuminate the high beam indica-
tor via the CAN bus line. The combination meter receives the 
transmitted signal and turns the high-beam indicator on and off.

AC306461

Headlight switch

ON

OFF

Headlight (Low)

ON

OFF

ON

OFF

Headlight 
relay (High)

ON

OFF

High-beam 
indicator light

ON

OFF

Front ECU
acknowdge

Hi-beam

ACK

OTHERS

Passing/Dimmer
switch

ON

PASS

OFF

AB

<2-bulb type>

<4-bulb type>

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-302

Headlight automatic-shutdown function
Even if the lighting switch (taillights switch or headlight switch) 
is ON, the headlights (including the taillights) will automatically 
go off in the following conditions to prevent the battery from dis-
charging as a result of forgetting to turn off lights.
If the ignition key is turned from "ON" to "LOCK" (OFF) or 
"ACC" position with the lighting switch turned ON, and this 
state continues for three minutes, the light will automatically be 
turned off. If the driver's seat door is opened during these three 
minutes, the light will go off one second later.
NOTE: The headlight automatic-shutoff function can be cus-
tomized on vehicles equipped with a multi center display (mid-
dle grade type). Refer to 

P.54B-578

.

Dimmer automatic reset function
If the headlight switch is turned off while the high-beam head-
lights are on, the dimmer switch will be reset. Because of this, 
the headlights will illuminate at low beam the next time that they 
are turned on. The dimmer switch will be also reset if the dim-
mer switch is turned on unintentionally while the passing switch 
is operated.

AC101466AB

T1: 3 minutes
T2: 1 second

ON

ON

ON

OFF

OFF

OFF

Ignition switch 
(IG1)

Driver's door 
switch

Taillight switch or 
headlight switch

Illumination 
output signal

ON

OFF

T1

T2

AC106399

ON

OFF

ON

OFF

Dimmer
switch

Headlight
switch

HIGH

LOW

OFF

Headlight

AC