Mitsubishi 380. Manual - part 106

INPUT SIGNAL PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-421

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

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. Connect special tool MB991910 before con-
necting 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 "ON" position.
(3) Operate the diagnostic tool 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 (MUT-III) should show "OK" on the "ECU 

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

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

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

with the column switch (column-ECU) is not possible 

P.54B-68

."

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC302210

COLUMN SWITCH 
CONNECTOR

COLUMN SWITCH 
CONNECTOR AT 
HARNESS SIDE 

MB991812

AB

INPUT SIGNAL PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-422

STEP 2. Check the turn-signal lamp and lighting switch.
Remove the turn-signal lamp and the lighting switch. Then 
check continuity between the switch terminals.

Q: Are the turn-signal lamp and lighting switch in good 

condition?
YES : Go to Step 3.
NO :  Replace the turn-signal lamp and the lighting switch. 

The input signal from the column switch (turn-signal 
lamp and lighting switch) should be able to be 
checked and the functions described in the "CIRCUIT 
OPERATION" should work normally.

STEP 3. Replace the column switch.
(1) Replace the column switch.
(2) The input signal from the column switch (turn-signal lamp 

and lighting switch) should be able to be checked and the 
functions described in the "CIRCUIT OPERATION" should 
work normally.

Q: Is the input signal from the column switch (turn-signal 

lamp and lighting switch) input normal?
YES : No action is necessary and testing is complete.
NO :  Replace the ETACS-ECU. The input signal from the 

column switch (turn-signal lamp and lighting switch) 
should be able to be checked and the functions 
described in the "CIRCUIT OPERATION" should work 
normally.

SWITCH 
POSITION

TESTER 
CONNECTION

SPECIFIED 
CONDITION

OFF

1 

− 2, 2 − 3, 2 − 11, 

2 

− 12, 5 − 9, 7 − 9

Open circuit

Taillight switch

5 

− 9

Less than 2 ohms

Headlamp switch

5 

− 9, 7 − 9

Less than 2 ohms

Passing switch

2 

− 12

Less than 2 ohms

Dimmer switch

2 

− 11, 2 − 12

Less than 2 ohms

Turn-signal lamp 
switch (LH)

1 

− 2

Less than 2 ohms

Turn-signal lamp 
switch (RH)

2 

− 3

Less than 2 ohms

AC003177

UPPER SIDE

AB

INPUT SIGNAL PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-423

INSPECTION PROCEDURE M-6: Column switch: ETACS-ECU does not receive any signal from the 
windshield mist wiper switch, the windshield intermittent wiper switch, the windshield low-speed 
wiper switch, the windshield high-speed wiper switch or the windshield washer switch.

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 operates the windshield wiper and 
washer according to signal from the windshield wiper 
and washer switch.

.

TECHNICAL DESCRIPTION (COMMENT)

If the signal is not normal, the windshield wiper and 
washer do not work normally.

.

TROUBLESHOOTING HINTS

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

• The column switch may be defective (windshield 

wiper and washer switch)

• 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

INPUT SIGNAL PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-424

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

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. Connect special tool MB991910 before con-
necting 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 "ON" position.
(3) Operate the diagnostic tool 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 (MUT-III) should show "OK" on the "ECU 

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

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

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

with the column switch (column-ECU) is not possible 

P.54B-68

."

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC302210

COLUMN SWITCH 
CONNECTOR

COLUMN SWITCH 
CONNECTOR AT 
HARNESS SIDE 

MB991812

AB