Mitsubishi 380. Manual — part 940

MULTI-CENTER DISPLAY

CHASSIS ELECTRICAL

54A-294

TROUBLESHOOTING HINTS

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

• Malfunction of multi-centre display unit

• Malfunction of A/C-ECU

• The wiring harness or connectors may have

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

DIAGNOSIS

Required Special Tools:

• MB991958: Diagnostic Tool (MUT-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness A (Vehicles with CAN

communication system)

STEP 1. Using diagnostic tool MB991958, diagnose the
CAN bus line
Use diagnostic tool MB991958 to diagnose the CAN bus lines.
(1) Connect diagnostic tool MB991958 to the data link

connector.

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

Q: Is the check result satisfactory?

YES : Go to Step 2.
NO : Repair the CAN bus lines (Refer to GROUP 54C,

Diagnosis-Can Bus Diagnostic Chart

P.54C-15

). After

diagnosing the CAN bus lines, go to Step 3.

STEP 2. Using diagnostic tool MB991958, read A/C
diagnostic trouble code.
Check if an A/C system DTC is set.

Q: Is the DTC set?

YES : Refer to GROUP 55A, Auto A/C Diagnostic Trouble

Code Chart

P.55-9

and then go to Step 3 .

NO : Replace multi-centre display unit and then go to Step

3.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTI-CENTER DISPLAY

CHASSIS ELECTRICAL

54A-295

STEP 3. Retest the system
Check if the A/C operation screen is displayed normally.

Q: Is the check result satisfactory?

YES : The procedure is complete.
NO : Go to Step 1.

INSPECTION PROCEDURE 4: The Ambient Air Temperature Display Shows "COM ERROR" or
"

−−deg°C"

.

16DB402A

A-02 (GR)

CONNECTOR: A-02

A-02 HARNESS CONNECTOR:

AC305210

A-25 (BR)

AQ

CONNECTOR: A-25

16DB407A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

A/T

CONTROL

UNIT

54DB025A

C-02

C-29

C-101

CONNECTORS: C-02, C-29, C-101

16DB553A

C-16 (B)

CONNECTORS: C-05,C-15, C-16

C-15 (B)

C-05 (B)

MULTI-CENTER DISPLAY

CHASSIS ELECTRICAL

54A-296

CIRCUIT OPERATION

The A/C-ECU receives information on ambient air
temperature from the ambient air temperature sen-
sor. Then the information is sent to the multi-centre
display unit via CAN communication.

.

TECHNICAL DESCRIPTION (COMMENT)

If the A/C-ECU has not informed an ambient air tem-
perature via the CAN communication for 60 seconds
or more, "COM ERROR" appears on the screen. If
the multi-centre display unit can not receive correct
information from the ambient air temperature sensor
at all, "

−−°C" will be shown.

.

TROUBLESHOOTING HINTS

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

• Malfunction of multi-centre display unit

• Malfunction of A/C-ECU

• Malfunction of Ambient air temperature sensor.

• The wiring harness or connectors may have

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

MULTI-CENTER DISPLAY

CHASSIS ELECTRICAL

54A-297

DIAGNOSIS

Required Special Tools:

• MB991958: Diagnostic Tool (MUT-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness A (Vehicles with CAN

communication system)

STEP 1. Using diagnostic tool MB991958, diagnose the
CAN bus line
Use diagnostic tool MB991958 to diagnose the CAN bus lines.
(1) Connect diagnostic tool MB991958 to the data link

connector.

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

Q: Is the check result satisfactory?

YES : Go to Step 2.
NO : Repair the CAN bus lines (Refer to GROUP 54C,

Diagnosis-Can Bus Diagnostic Chart

P.54C-15

). After

diagnosing the CAN bus lines, go to Step 3.

STEP 2. Using diagnostic tool MB991958, read A/C
diagnostic trouble code.
Check if an A/C system DTC is set.

Q: Is the DTC set?

YES : Refer to GROUP 55A, Auto A/C Diagnostic Trouble

Code Chart

P.55-9

and then go to Step 3 .

NO : Replace multi-centre display unit and then go to Step

3.

STEP 3. Retest the system
Check if the ambient air temperature operation screen is dis-
played normally.

Q: Is the check result satisfactory?

YES : The procedure is complete.
NO : Go to Step 1.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827