Mitsubishi Galant (2004+). Manual — part 1509

MULTI-CENTER DISPLAY

TSB Revision

CHASSIS ELECTRICAL

54A-279

.

CIRCUIT OPERATION
The multi-center display unit (middle grade type)
receives information on current A/C operation condi-
tion from the A/C-ECU via CAN bus lines.

.

TECHNICAL DESCRIPTION (COMMENT)
The multi-center display unit (middle grade type) will
show "COMMUNICATION ERROR" message if it
has received abnormal data from the A/C-ECU via
CAN communication for 60 seconds or more. Then
the A/C operation screen, which is based on the last
normal information, continues to be shown. If the
communication returns to normal, "COMMUNICA-
TION ERROR" message will disappear and the A/C
operation screen will return to normal.

.

TROUBLESHOOTING HINTS

• Malfunction of multi-center display unit (middle

grade type)

• 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: Scan 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)

AC305206

CONNECTOR: A-02

AO

A-02 (GR)

AC305216

B-19 (B)

CONNECTOR: B-19

AD

AC305231

C-02

C-29

C-101

DD

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

AC305233

CONNECTORS: C-05, C-15

CQ

C-05 (B)

C-15 (B)

MULTI-CENTER DISPLAY

TSB Revision

CHASSIS ELECTRICAL

54A-280

STEP 1. Using scan tool MB991958, diagnose the CAN bus
line
Use scan tool MB991958 to diagnose the CAN bus lines.
(1) Connect scan 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-14

). After

diagnosing the CAN bus lines, go to Step 3.

STEP 2. Using scan 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, Manual A/C Diagnosis

−

Diagnostic Trouble Code Chart <Low Type>

P.55A-10

or GROUP 55A, Diagnostic Trouble Code Chart
<Middle Type>

P.55A-59

or Auto A/C Diagnostic

Trouble Code Chart

P.55B-8

and then go to Step 3 .

NO : Replace multi-center display unit (middle grade type)

and then go to Step 3.

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.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTI-CENTER DISPLAY

TSB Revision

CHASSIS ELECTRICAL

54A-281

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

−−deg°C (−−°F)." (Middle Grade Type)

A/C-ECU

JOINT
CONNECTOR (3)

JOINT
CONNECTOR (2)

COMBINATION
METER

AMBIENT AIR
TEMPERATURE
SENSOR

CPU

MULTI-CENTER
DISPLAY UNIT

ABS-ECU OR ABS/TCL-ECU

WITHOUT ELECTRONIC
BRAKE-FORCE
DISTRIBUTION (EBD)
AND ANTI-LOCK
BRAKING SYSTEM
(ABS)

WITHOUT ELECTRONIC
BRAKE-FORCE
DISTRIBUTION (EBD)
AND ANTI-LOCK
BRAKING SYSTEM
(ABS)

WITH ELECTRONIC
BRAKE-FORCE
DISTRIBUTION (EBD)
AND ANTI-LOCK
BRAKING SYSTEM
(ABS)

WITH ELECTRONIC
BRAKE-FORCE
DISTRIBUTION (EBD)
AND ANTI-LOCK
BRAKING SYSTEM
(ABS)

POWERTRAIN
CONTROL
MODULE

CAN-BUS Line and Ambient Air Temperature Sensor Circuit

MULTI-CENTER DISPLAY

TSB Revision

CHASSIS ELECTRICAL

54A-282

.

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-center
display unit (middle grade type) via CAN communi-
cation.

.

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-center display unit (middle grade type) can
not receive correct information from the ambient air
temperature sensor at all, "

−−°C (−−°F)" will be

shown.

.

TROUBLESHOOTING HINTS

• Malfunction of multi-center display unit (middle

grade type)

• 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.

AC305206

CONNECTOR: A-02

AO

A-02 (GR)

AC305210

A-25 (BR)

AQ

CONNECTOR: A-25

AC305216

B-19 (B)

CONNECTOR: B-19

AD

AC305231DE

CONNECTORS: C-02, C-03, C-29, C-101

C-02

C-03

C-29

C-101

AC305233

C-16 (B)

C-23

CONNECTORS: C-05,C-15, C-16,C-23

C-15 (B)

CR

C-05 (B)