Mitsubishi 380. Manual - part 28

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-109

STEP 4. Use diagnostic tool MB991958 to select "ECU 
COMM Check" on the SWS monitor display. 
Check the ETACS-ECU.

CAUTION

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 SWS monitor. Refer to "How to connect SWS 

monitor 

P.54B-13

."

(2) Turn the ignition switch to the "ON" position.
(3) Operate diagnostic 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) diagnostic 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 5.
NO :  Refer to Inspection Procedure A-3 "Communication 

with the ETACS-ECU is not possible 

P.54B-74

."

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC302210

COLUMN SWITCH 
CONNECTOR

COLUMN SWITCH 
CONNECTOR AT 
HARNESS SIDE 

MB991812

AB

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-110

STEP 5. 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

• Vehicle speed: 8 km/h (5 mph) or more

(1) Operate diagnostic 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 diagnostic tool MB991958 display changes 
when the driver's or the front passenger's door is opened. If 
any of the doors are open, the system cannot be checked 
correctly.

Q: Does diagnostic tool MB991958 display the items "IG 

SW (IG1)", "FRONT DOOR SW" and "BUZZER" as 
normal condition?
Normal conditions are displayed for all the items : Go to 

Step 6.

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-408

."

Normal condition is not displayed for "FRONT DOOR 
SW" : Refer to Inspection Procedure M-4 "ETACS-ECU 

does not receive any signal from the front door 
switches 

P.54B-413

."

Normal condition is not displayed for "BUZZER" : 

Replace the ETACS-ECU. The ignition key reminder 
tone alarm function should now work normally.

ITEM NO.

ITEM NAME

NORMAL 
CONDITION

ITEM 30

IG SW (IG1)

ON

ITEM 32

FRONT DOOR SW

ON

ITEM 43

BUZZER

ON

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC302210

COLUMN SWITCH 
CONNECTOR

COLUMN SWITCH 
CONNECTOR AT 
HARNESS SIDE 

MB991812

AB

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-111

STEP 6. Check the input signal (by using the pulse check 
mode of the monitor).
Check the following switches and input signals:

• Doors switches

(1) Operate diagnostic 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 diagnostic tool MB991958 sounds or not.

Q: When any door switch is operated, does diagnostic tool 

MB991958 sound?
YES : Replace the ETACS-ECU. The door ajar warning 

buzzer function should now work normally.

NO :  Refer to Inspection Procedure N-3 "ETACS-ECU 

does not receive any signal from any of the door 
switches 

P.54B-440

."

ITEM NAME

CONDITION

door switch

Open or close one of the doors

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-112

INSPECTION PROCEDURE B-5: Tone Alarm: The Multi center Display does not Sound Normally When 
it is Operated. <Multi center Display>

NOTE: This troubleshooting procedure requires the 
use of diagnostic tool MB991958 and SWS monitor 
kit MB991813. For details on how to use the SWS 
monitor, refer to "How to connect SWS monitor 

P.54B-13

."

.

CIRCUIT OPERATION

The ETACS-ECU sounds the buzzer when it 
receives buzzer signal from the multi center display 
(MID).

.

TECHNICAL DESCRIPTION (COMMENT)

If this function does not work normally, connector(s), 
wiring harness in the CAN bus lines, the mid-
dle-grade multi center display unit 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

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB991958: diagnostic 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: Test Probe Harness

STEP 1. Check the operation of the multi center display 
(MID).

Q: Does the multi center display work normally?

YES : Go to Step 2.
NO :  First, replace the multi center display unit.

ETACS-

ECU

MULTI CENTER

DISPLAY UNIT

CAN COMMUNICATION LINE

(CAN_L LINE)

CAN COMMUNICATION LINE

(CAN_H LINE)

Multi Center Display Annunciation Function