Mitsubishi Galant 9G. Manual — part 42

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-164

INSPECTION PROCEDURE C-6: Central Door Locking System: Forgotten Key Prevention Function
does not Work Normally.

NOTE: This troubleshooting procedure requires 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

."

.

CIRCUIT OPERATION

The ETACS-ECU operates the forgotten key preven-
tion function according to the following switches:

• Key reminder switch: OFF

• Front door switch: ON

• Front door lock actuator switch: being turned on

The ETACS-ECU operates the forgotten key preven-
tion function under the following conditions:

• Ignition key: inserted into the ignition key cylinder

• Front door: open

• Front door lock: being locked

.

TECHNICAL DESCRIPTION (COMMENT)

If the function does not work normally, the input cir-
cuit system from the switches or the ETACS-ECU
may be defective (refer to "CIRCUIT OPERATION").

.

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

DOOR LOCK ACTUATOR

INPUT SIGNAL

·DRIVER'S DOOR LOCK ACTUATOR SWITCH

FUSIBLE
LINK

1

JUNCTION BLOCK SIDE

JUNCTION
BLOCK

ETACS-ECU

·FRONT DOOR SWITCH
·FRONT PASSENGER'S DOOR LOCK
ACTUATOR SWITCH
·KEY REMINDER SWITCH

UNLOCK
RELAY

LOCK
RELAY

( )

( )

Forgotten Key Prevention Circuit

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-165

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

STEP 1. Use scan tool MB991958 to select "ECU COMM
Check" on the SWS monitor display.
Check the ETACS-ECU.

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958. Connect
special tool MB991910 before connecting special tool
MB991812. Be sure to connect special tool MB991806 after
turning on special tool MB991824.
(1) Connect the special tool. Refer to "How to connect SWS

monitor

P.54B-13

."

(2) Turn the ignition switch to the "LOCK" (OFF) position.
(3) Operate scan tool MB991958 according to the procedure

below to display "ECU COMM Check."
a. Select "Interactive Diagnosis."
b. Select "System Select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "ECU COMM Check."

(4) Scan tool MB991958 should show "OK" on the "ECU

COMM Check" menu for the "ETACS ECU" menu.

Q: Is "OK" displayed for the "ETACS ECU" menu?

YES : Go to Step 2.
NO : Refer to Inspection Procedure A-3 "Communication

with the ETACS-ECU is not possible

P.54B-78

."

AC305411AB

MB991910

DATA LINK

CONNECTOR

MB991827

MB991824

MB991806

MB991812

AC302210

COLUMN SWITCH
CONNECTOR

COLUMN SWITCH
CONNECTOR AT
HARNESS SIDE

MB991812

AB

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-166

STEP 2. Check the input signal by using "DATA LIST"
menu of the SWS monitor.
Turn the ignition switch to the "ON" position before checking
input signals from the ignition switch (IG1).
(1) Operate the 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 items

described in the table below.

Q: Does scan tool MB991958 display "FRONT DOOR SW"

as normal condition?
YES : Go to Step 3.
NO : Refer to Inspection Procedure M-4 "ETACS-ECU

does not receive any signal from the front door
switches

P.54B-477

."

ITEM NO.

ITEM NAME

NORMAL CONDITION

ITEM 32

FRONT DOOR SW ON

AC305411AB

MB991910

DATA LINK

CONNECTOR

MB991827

MB991824

MB991806

MB991812

AC302210

COLUMN SWITCH
CONNECTOR

COLUMN SWITCH
CONNECTOR AT
HARNESS SIDE

MB991812

AB

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-167

STEP 3. Check the input signal (by using the pulse check
mode of the monitor).
Check the following switches and input signals:

• Key reminder switch

• Door switches

(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 is

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

Replace the ETACS-ECU. The forgotten key
prevention function should work normally.

When the ignition key is removed and inserted, scan
tool MB991958 does not sound. : Refer to Inspection

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

P.54B-497

."

When one of the doors is opened and closed, scan tool
MB991958 does not sound : Refer to Inspection

Procedure N-3 "ETACS-ECU does not receive any
signal from any of the door switches

P.54B-505

."

POWER WINDOWS

GENERAL DESCRIPTION CONCERNING THE POWER WINDOWS

M1549021900244

The following ECUs affect the functions and control
of the power windows.

ITEM NAME

CONDITION

key reminder switch Remove and reinsert the ignition key

Door switches

Open or close one of the doors

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

FUNCTION

CONTROL ECU

Power window main
switch function

Raises the driver’s power window

Power window main switch

Lowers the driver’s power window

Power window main switch

Lowers the driver’s power window by one-touch down
function

Power window main switch

Raises the passenger’s power window

Power window main switch

Lowers the passenger’s power window

Power window main switch

Power window sub
switch function

Raises the passenger’s power window

Power window sub switch

Lowers the passenger’s power window

Power window sub switch

Power window timer function

ETACS-ECU