Mitsubishi 380. Manual - part 56

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-221

STEP 1. Use diagnostic tool MB991958 to select "ECU 
COMM Check" on the SWS monitor display. 
Check the following ECUs:

• ETACS-ECU

• Sunroof-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 "LOCK" (OFF) position.
(3) Operate the 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 "ETACS ECU" and the 
"SUNROOF ECU" menus.

Q: Is "OK" displayed for both the "ETACS ECU" and 

"SUNROOF ECU" menus?
"OK" is displayed for all the items : Go to Step 2.
"NG" is displayed for the "ETACS ECU" menu : Refer to 

Inspection Procedure A-3 "Communication with the 
ETACS-ECU is not possible 

P.54B-74

."

"NG" is displayed for the "SUNROOF ECU" menu : 

Refer to Inspection Procedure A-5 "Communication 
with the sunroof-ECU is not possible 

P.54B-87

."

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-222

STEP 2. Check the input signal by using "FUNCTION 
DIAG." menu of the SWS monitor.
Observe how the input signal is changed when the ignition 
switch is turned from the ON position to the "LOCK" (OFF) 
position.
(1) Operate the MUT-III according to the procedure below to 

display "SUNROOF-OPE."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f.

Select "SUNROOF."

g. Select "SUNROOF-OPE."

(2) Check that normal conditions are displayed for the items 

described in the table below.

Q: Does the MUT-III display the items "IG SW (IG1)" and 

"S/R ECU ACK" as normal condition?
Normal conditions displayed for all the items : Replace 

the sunroof motor assembly. Check that the sunroof 
timer function works normally.

Normal condition is not displayed for the "IG SW (IG1)" : 

Refer to Inspection Procedure M-2 "ETACS-ECU 
does not receive a signal from the ignition switch 
(IG1) 

P.54B-408

."

Normal condition is not displayed for the "S/R ECU 
ACK" : Replace the sunroof motor assembly. Check that the 

sunroof timer function works normally.

ITEM NO.

ITEM NAME

NORMAL 
CONDITION

ITEM 30

IG SW (IG1)

OFF

ITEM 72

S/R ECU ACK

NORMAL ACK

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC302210

COLUMN SWITCH 
CONNECTOR

COLUMN SWITCH 
CONNECTOR AT 
HARNESS SIDE 

MB991812

AB

NEXT PAGE

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-223

54B

WINDSHIELD WIPER AND WASHER

GENERAL DESCRIPTION CONCERNING THE WINDSHIELD WIPER AND WASHER

M1549021500257

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

The following ECUs affect the functions and control 
of the windshield wiper and washer.

Windshield wiper and washer control function

.

Intermittent control (vehicle speed-dependent 
variable type)

ETACS-ECU uses the dial position of the variable intermittent 
wiper control switch and the vehicle speed signal sent by the 
combination meter to calculate the interval to be sent to the 
front-ECU.

NOTE: The speed-sensitive wiper can be customized on vehi-
cles equipped with a multi center display (middle grade type). 
Refer to 

P.54B-486

.

The front-ECU determines the intermittent time T1 from the 
input SWS data signal, and turns ON the windshield wiper drive 
signal. When the wiper is at the STOP position, the windshield 
wiper auto-stop signal goes OFF, then turns OFF the wind-
shield wiper drive signal. After the intermittent time T1 seconds 
from when the windshield wiper drive signal turned ON, the 
windshield wiper drive signal is turned ON again and the above 
operation is repeated.

NOTE: If the intermittent time T1 is within 2 seconds, the wiper 
is operated consecutively at LOW-speed by the front-ECU.

.

FUNCTION

CONTROL ECU

Windshield wiper and washer 
control function

Intermittent control (Vehicle 
speed-dependent variable type)

ETACS-ECU, front-ECU, column 
switch

Mist wiper control

ETACS-ECU, column switch

Low speed wiper and high speed 
wiper control

ETACS-ECU, column switch

Washer control

ETACS-ECU, column switch

AC305397

Intermittent 

time T1 

(seconds)

Variable intermittent wiper

control switch position

Intermittent 

time T1 

(seconds)

Vehicle speed  (km/h)

When at SLOW position

Change in intermittent time 

according to vehicle speed

Change in intermittent time by variable 

intermittent wiper control switch (when 

vehicle is stationary)

0

100

19.0

0

FAST

SLOW

19.0

AB

60

4.6

14.0

4.6

1.6

When at FAST position

2.0

AC200355AC

ON

OFF

ON

OFF

WINDSHIELD

WIPER 

AUTOSTOP 

SIGNAL

WINDSHIELD

WIPER DRIVE

SIGNAL

T1

T1

T1: Intermittent time

PREVIOUS PAGE

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-224

Mist wiper control

When the ignition switch is in the ACC or ON posi-
tion, and the windshield mist wiper switch is turned 
ON, the front-ECU turns ON the windshield wiper 
drive signal. At the same time, the wiper speed 
switching relay is turned ON (HIGH-SPEED). While 
the windshield mist wiper switch is ON, the wind-
shield wiper will operate at high speed. Then, if the 
windshield mist wiper switch is turned off, the wiper 
operates at low speed until it stops at the predeter-
mined park position.

When the windshield mist switch is turned on briefly, 
the wiper operates once at low speed.
At the point the windshield mist switch is turned ON, 
if the windshield wiper has been operating intermit-
tently, the same operations as the above will be per-
formed while the windshield mist wiper switch is ON. 
After the windshield mist wiper switch goes OFF, the 
intermittent operations will be set again T1 seconds 
after the last windshield wiper auto-stop signal turn-
ing ON.

.

Low speed wiper and high speed wiper control

When the ignition switch is at the ACC or ON posi-
tion, and the windshield low speed wiper switch of 
the column switch is turned ON, the front-ECU turns 
ON the windshield wiper drive signal, turns OFF (LO) 
the windshield wiper speed relay, and operates the 

windshield wiper at low speed. Next, when the wind-
shield high speed wiper switch is turned ON, the 
windshield wiper drive signal is turned ON, the wind-
shield wiper speed switching relay is turned ON (HI), 
and the windshield wiper is operated at high speed.

.

AC200047AB

ON

OFF

ON

OFF

ON

OFF

ON (HIGH)

Windshield mist wiper switch

Windshield wiper auto-stop 
signal

Windshield wiper drive signal

Windshield wiper speed 
switching relay

OFF (LOW)

When windshield 
wiper switch is OFF

When windshield intermittent 
wiper is operating

T1: Intermittent time

T1

T1

AC005437AF

ON

OFF

ON

OFF

ON

OFF

ON (HIGH)

Windshield low-speed 
wiper switch

Windshield high-speed 
wiper switch

Windshield wiper auto-stop 
signal

ON

OFF

Windshield wiper 
drive signal
Windshield wiper 
speed switching relay OFF (LOW)

Low speed operations

High speed operations