Mitsubishi 380. Manual - part 29

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-113

STEP 2. Using diagnostic tool MB991958, diagnose the 
CAN bus line.

CAUTION

To prevent damage to diagnostic tool MB991958, always 
turn the ignition switch to the "LOCK" (OFF) position 
before connecting or disconnecting diagnostic tool 
MB991958.
(1) Connect diagnostic tool MB991958. Refer to "How to 

connect SWS monitor 

P.54B-13

."

(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?

YES : Go to Step 3.
NO :  Repair the CAN bus line (Refer to GROUP 54C, 

Diagnosis 

P.54C-13

).

STEP 3. Using diagnostic tool MB991958, read the multi 
center display diagnostic trouble code.
Check that a multi center display DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the multi center display DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Diagnose the multi center display unit (Refer to 

GROUP 54A, Diagnosis 

P.54A-254

).

NO :  Go to Step 4.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-114

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-115

STEP 5. Check the input signal by using "FUNCTION 
DIAG." menu of the SWS monitor.
Turn the ignition switch to the "ON" position to check the input 
signals from the following switches.
(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: If the function switch of the multi center display is 
operated, check that No.43 "BUZZER" is displayed as nor-
mal condition.

Q: Are normal conditions displayed for the "IG SW (IG1)" 

and "BUZZER"?
Normal conditions are displayed for all the items : 

Replace the ETACS-ECU. Verify that the multi center 
display operating sound 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-408

."

Normal condition is not displayed for "BUZZER" : 

Replace the ETACS-ECU. Verify that the multi center 
display operating sound function works normally.

ITEM NO.

ITEM NAME

NORMAL 
CONDITION

ITEM 30

IG SW (IG1)

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-116

INSPECTION PROCEDURE B-6: Tone Alarm: Turn-signal Lamp Buzzer Function does not Work 
Normally.

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

P.54B-13

."

.

CIRCUIT OPERATION

The ETACS-ECU controls the turn-signal lamp 
buzzer function, based on the switch signals below:

• Turn-signal lamp switch: ON

• Hazard switch: ON

.

TECHNICAL DESCRIPTION (COMMENT)

If the turn-signal lamp buzzer function does not work 
normally, connector(s), wiring harness, the column 
switch, the ETACS-ECU or the input signal circuit 
may be defective.

.

TROUBLESHOOTING HINTS

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

• 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

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 adjustment function.

Q: Has the turn-signal lamp buzzer function been enabled 

by the adjustment function?
YES : Go to Step 2.
NO :  Enable the turn-signal lamp buzzer function.

ETACS-

ECU

· 

HAZARD WARNING LIGHT

 SWITCH

· 

TURN-SIGNAL LIGHT

 SWITCH

Turn-signal Annunciation Function