Mitsubishi 380. Manual - part 76

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-301

STEP 25. Check the wiring harness between headlamp 
(RH) connector A-32 (terminals 5 and 1) and ground.
Q: Is the wiring harness between headlamp (RH) connector 

A-32 (terminals 5 and 1) and ground 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 headlamps illuminate normally.

INSPECTION PROCEDURE H-8: Headlamp and Taillamp: The High-beam indicator lamp does not 
illuminate.

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

At the same time that the high beams are illumi-
nated, the ETACS-ECU sends a signal to illuminate 
the high beam indicator via the CAN bus line.

.

TECHNICAL DESCRIPTION (COMMENT)

If the high beam indicator does not illuminate nor-
mally, connector(s), wiring harness in the CAN bus 
lines, the ETACS-ECU or the combination meter may 
be defective.

.

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 combination meter may be defective

• The ETACS-ECU may be defective

.

16DB433A

A-32

CONNECTORS:   A-32

INPUT SIGNAL

ETACS-

ECU

DIMMER SWITCH

COMBINATION

METER

CAN COMMUNICATION LINE

(CAN_L LINE)

CAN COMMUNICATION LINE

(CAN_H LINE)

High-Beam Indicator Light Circuit

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-302

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 headlamps.
When the lighting switch is operated, check that the headlamps 
illuminate/go off normally.

Q: Are the headlamps in good condition?

YES : Go to Step 2.
NO :  First, repair the headlamps. Refer to Inspection 

Procedure H-7 "One of the headlamps does not 
illuminate 

P.54B-290

."

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-15

).

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-303

STEP 3. Using Diagnostic Tool MB991958, read the 
combination meter diagnostic trouble code.
Check whether a combination meter-related DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check whether the combination meter-related DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Diagnose the combination meter. Refer to 

P.54A-48

.

NO :  Go to Step 4.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SYMPTOM PROCEDURES

SIMPLIFIED WIRING SYSTEM (SWS)

54B-304

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 "LOCK" (OFF) 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

."

STEP 5. Replace the combination meter.
(1) Replace the combination meter.
(2) Check that the high beam indicator lamp illuminates 

normally.

Q: Does the high beam indicator lamp illuminate normally?

YES : No action is necessary and testing is complete.
NO :  Replace the ETACS-ECU. Check that the high beam 

indicator lamp illuminates normally.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC302210

COLUMN SWITCH 
CONNECTOR

COLUMN SWITCH 
CONNECTOR AT 
HARNESS SIDE 

MB991812

AB