Mitsubishi Galant 9G. Manual — part 34

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-132

STEP 4. Check the input signal by using "FUNCTION
DIAG." menu of the SWS monitor.
Check the input signals from the following switches:

• Ignition switch: ON

• Driver’s door: Open

• All door: Closed

(1) Operate scan tool MB991958 according to the procedure

below to display "OTHER ALARM"
a. Select "Interactive Diagnosis."
b. Select "System Select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f. Select "BUZZER."
g. Select "OTHER ALARM"

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

described in the table below.
NOTE: The scan tool MB991958 display changes when the
driver's or the front passenger's door is opened. If any of the
doors is open, the system cannot be checked correctly.

Q: Does scan tool MB991958 display the items "IG SW

(IG1)" and "BUZZER" as normal condition?
Normal conditions are displayed for all the items :

Replace the ETACS-ECU. Check that the turn-signal
light buzzer function works normally.

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

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

P.54B-470

."

Normal condition is not displayed for "BUZZER" :

Replace the ETACS-ECU. Check that the turn-signal
light buzzer function works normally.

CENTRAL DOOR LOCKING SYSTEM

GENERAL DESCRIPTION CONCERNING CENTRAL DOOR LOCKING SYSTEM

M1549021100271

The following ECUs affect the functions and control
of the central door locking system.

ITEM NO.

ITEM NAME

NORMAL
CONDITION

ITEM 30

IG SW (IG1)

ON

ITEM 43

BUZZER

ON

AC305411AB

MB991910

DATA LINK

CONNECTOR

MB991827

MB991824

MB991806

MB991812

AC302210

COLUMN SWITCH
CONNECTOR

COLUMN SWITCH
CONNECTOR AT
HARNESS SIDE

MB991812

AB

FUNCTION

CONTROL ECU

Central door locking system

ETACS-ECU

Forgotten key prevention function

ETACS-ECU

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-133

CENTRAL DOOR LOCKING SYSTEM

.

DOOR UNLOCKING BY OPERATING THE
DRIVER’S DOOR LOCK KEY CYLINDER

When the ignition key is inserted in the driver’s door lock key
cylinder and turned clockwise to unlock the driver’s door, the
ETACS-ECU operates its door unlock relay and passes a cur-
rent through the door lock actuator of the driver’s door for 0.25
seconds to unlock only the driver’s door.
When the ignition key is turned clockwise again, the
ETACS-ECU operates its door unlock relay and passes a cur-
rent through the door lock actuators of all doors for 0.25 sec-
onds and to unlock all doors.
NOTE: Vehicles with a multi center display (middle grade type)
can be customized so that a single unlock operation will unlock
all doors. Refer to

P.54B-555

.

.

DOOR LOCKING OR UNLOCKING BY
OPERATING THE DRIVER’S OR FRONT
PASSENGER’S DOOR LOCK SWITCH

When the door is locked by the driver’s or front passenger’s
door lock switch, the ETACS-ECU operates its door lock relay
and passes a current through the door lock actuators of all
doors for 0.25 seconds to lock all doors.
When the door is unlocked by the driver’s or front passenger's
door lock switch, the ETACS-ECU operates its door unlock
relay and passes a current through the door lock actuators of
all doors for 0.25 seconds to unlock all doors.
When the door is locked and unlocked by driver’s or front pas-
senger's door lock switch consecutively, the ETACS-ECU oper-
ates its door lock relay and passes a current through the door
lock actuators of all doors for 0.25 seconds to lock all doors.
Then, the ETACS-ECU operates its door unlock relay and
passes a current through the door lock actuators of all doors for
0.25 seconds to unlock all doors. Due to this, there may be a
time lag between the driver’s or front passenger's door lock
switch actuation and the time when all doors are unlocked.

AC305383 AB

ON

(UNLOCK)

OFF

DRIVER'S
DOOR LOCK KEY
CYLINDER SWITCH

t: 0.25 SECOND

OFF

ON

DRIVER'S DOOR
UNLOCK RELAY
OUTPUT

LOCK

UNLOCK

LOCK

UNLOCK

DRIVER'S DOOR
LOCK ACTUATOR

t

ALL DOOR'S
LOCK ACTUATOR

t

OFF

ON

t

OTHER DOOR
UNLOCK RELAY
OUTPUT

AC305384

t

AB

ON

(LOCK)

ON

(UNLOCK)

ON

OFF

ON

OFF

DRIVER'S OR
FRONT
PASSENGER'S
DOOR LOCK
SWITCH

UNLOCK RELAY
OUTPUT

LOCK RELAY
OUTPUT

t: 0.25 SECOND

t

t

TIME LAG

t

t

OFF

LOCK

UNLOCK

ALL DOORS
LOCK
ACTUATOR

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-134

FORGOTTEN KEY PREVENTION FUNCTION

If the driver's door is locked while it is open

If the driver's door is locked while it is open and when
the key is still in the ignition key cylinder, approxi-
mately 0.3 second later the ETACS-ECU activates
the unlock relay output for 0.25 second to prevent
the door from being locked with the key inside the
vehicle.

In addition, if locking the door was not prevented, a
re-try current is sent (an unlock relay output ON is
sent for 0.25 second up to 5 times including the first
attempt).
NOTE: The dotted line indicates that the system is
trying to turn on the unlock relay if the door cannot be
unlocked.

If the front passenger's door is open when it is locked with the driver's door switch

AC209078AB

ON

OFF

ON

OFF

Lock relay output

Unlock relay output

LOCK

UNLOCK

Driver's door
lock actuator

ON (Key removed)

OFF (Key inserted)

Key reminder switch

t

ON (Driver's door is open)

Driver's door switch

OFF (Driver's door is closed)

t

t: 0.3 seconds
T1: 0.25 seconds
T2: 1 seconds

T2

T2

T2

T2

T1

T1

T1

T1

T1

T1

AC209079 AB

ON

OFF

ON

OFF

Lock relay output

Unlock relay output

LOCK

UNLOCK

Driver's door
lock actuator

LOCK

UNLOCK

Front passenger's door
lock actuator

ON (Key removed)

OFF (Key inserted)

Key reminder switch

t

ON (Front passenger's

door is open)

Front passenger's
door switch

OFF (Front passenger's

door is closed)

t

t

t

t: 0.3 seconds
T1: 0.25 seconds
T2: 1 seconds

T2

T2

T2

T2

T2

T2

T2

T2

T1

T1

T1

T1

T1

T1

T1

T1

T1

T1

T1

T1

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-135

If the passenger's door or driver's door are locked
while the passenger's door is open and when the key
is still in the ignition key cylinder, approximately 0.3
second later the ETACS-ECU activates the unlock
relay output for 0.25 second to prevent the door from
being locked with the key inside the vehicle.

In addition, if locking the door was not prevented, a
re-try current is sent (an unlock relay output ON is
sent for 0.25 second up to 5 times including the first
attempt).
NOTE: The dotted line indicates that the system is
trying to turn on the unlock relay if the door cannot be
unlocked.

GENERAL CIRCUIT DIAGRAM FOR THE CENTRAL DOOR LOCKING SYSTEM

FRONT DOOR
LOCK
ACTUATOR
(LH)

FRONT DOOR
LOCK
ACTUATOR
(RH)

REAR DOOR
LOCK
ACTUATOR
(LH)

REAR DOOR
LOCK
ACTUATOR
(RH)

FRONT DOOR
LOCK ACTUATOR (LH)

FRONT DOOR
LOCK ACTUATOR (RH)

DOOR LOCK
KEY CYLINDER
SWITCH

DATA LINK
CONNECTOR

JUNCTION BLOCK

ETACS-
ECU

1

FUSIBLE
LINK