Mitsubishi 380. Manual - part 59

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-233

NOTE: Also check intermediate connector C-29 for loose, cor-
roded, or damaged terminals, or terminals pushed back in the 
connector. If intermediate connector C-29 is damaged, repair or 
replace the damaged component(s) as described in GROUP 
00E, Harness Connector Inspection 

P.00E-2

.

Q: Is the wiring harness between front-ECU connector 

A-12X (terminal 28) and the ignition switch (ACC) in 
good condition?
YES : No action is necessary and testing is complete.
NO :  The wiring harness may be damaged or the 

connector(s) may have loose, corroded or damaged 
terminals, or terminals pushed back in the connector. 
Repair the wiring harness as necessary. Verify that 
the windshield wiper works normally.

16DB353A

CONNECTOR: C-29

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-234

INSPECTION PROCEDURE G-2: Windshield Wiper and Washer: The windshield wipers do not work 
when the windshield wiper switch is at "INT" or "MIST" position or the windshield washer switch is at 
"ON" position. However, the wipers work at low speed when the windshield wiper switch is at "LO" or 
"HI."

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

."

.

TECHNICAL DESCRIPTION (COMMENT)

This system may be at fail-safe mode as the SWS 
communication line is defective.
If the system cannot receive any signal from the col-
umn switch (windshield wiper and washer switch) 
due to a open circuit in the SWS communication line 
or other reasons, the system will enter the fail-safe 
mode when the ignition switch is at the "ACC" posi-
tion.

.

TROUBLESHOOTING HINTS

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

• The wiring harness or connectors may have 

loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector

• The column switch may be defective

• The front-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

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-235

Use Diagnostic Tool MB991958 to select "ECU COMM 
Check" on the SWS monitor display. 
Check the following ECUs:

• Column-ECU

• Front-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 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" menus for both the "COLUMN ECU" and 
the "FRONT ECU" menus.

Q: Is "OK" displayed for the "COLUMN ECU" and "FRONT 

ECU" menu?
"OK" is displayed for all the items : Replace the 

front-ECU. Verify that the windshield wiper works 
normally.

"NG" is displayed for the "COLUMN ECU" menu : Refer 

to Inspection Procedure A-2 "Communication with the 
column switch (column-ECU) is not possible 

P.54B-68

."

"NG" is displayed for the "FRONT ECU" menu : Refer to 

Inspection procedure A-4 "Communication with the 
front-ECU is not possible 

P.54B-80

."

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-236

INSPECTION PROCEDURE G-3: Windshield Wiper and Washer: All of the windshield wiper switch 
positions are defective.

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

."

.

TECHNICAL DESCRIPTION (COMMENT)

If either of the windshield wiper switch positions is 
defective, the windshield wiper motor, column switch 
(windshield wiper and washer switch) or the 
front-ECU 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 wiper motor may be defective

• The front-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

16DB425A

A-03 (B)

CONNECTOR: A-03

AC305977

CONNECTOR: A-12X

AF