Mitsubishi Galant (2004+). Manual - part 1510

MULTI-CENTER DISPLAY

TSB Revision

CHASSIS ELECTRICAL

54A-283

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)

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 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 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.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTI-CENTER DISPLAY

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CHASSIS ELECTRICAL

54A-284

INSPECTION PROCEDURE 5: On the Audio Screen, "COMMUNICATION ERROR" can not Proceed to 
Next Screen. (Middle Grade Type)

.

CIRCUIT OPERATION
The multi-center display unit (middle grade type) 
receives information from the radio, CD player and 
CD changer via M bus communication to display the 
audio system operation condition.

.

TECHNICAL DESCRIPTION (COMMENT)
The audio system operation screen will be frozen if 
the multi-center display (middle grade type) have 
received abnormal data from the radio, CD player 
and CD changer via M-bus communication within 30 
seconds. If the abnormal data is received further 30 
seconds from that point, a message "COMMUNICA-
TION ERROR" will be displayed.

.

TROUBLESHOOTING HINTS

• Malfunction of multi-center display unit (middle 

grade type)

• Malfunction of radio, CD player and CD changer

• The wiring harness or connectors may have 

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

MULTI-CENTER  
DISPLAY UNIT

RADIO, CD PLAYER AND CD CHANGER

M-BUS Line Circuit

AC305233CL

CONNECTORS: C-05, C-117

C-05 (B)

C-117

MULTI-CENTER DISPLAY

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CHASSIS ELECTRICAL

54A-285

DIAGNOSIS 

Required Special Tools:

• MB991223: Harness Set

STEP 1. Check the communication condition by 
self-diagnostic function.
1.Start up the service mode to check the communication condi-
tion (Refer to 

P.54A-228

). 

Q: Is "NG" displayed as the check results for M-bus 

communication?
YES : Go to Step 2.
NO :  Go to Step 4.

STEP 2. Check radio, CD player and CD changer connector 
C-117 and multi-center display unit (middle grade type) 
connector C-05 for loose, corroded or damaged terminals, 
or terminals pushed back in the connector.
Q: Is radio, CD player and CD changer connector C-117 

and multi-center display unit (middle grade type) 
connector C-05 in good condition?
YES : Go to Step 3.
NO :  Repair or replace the component(s). Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Then go 

to step 1.

Communication check result

M-BUS             : OK
CAN-BUS        : OK

AC208700 AC

AC305234

CONNECTORS: C-05, C-117

C-05 (B)

C-117

HARNESS SIDE

C-05

HARNESS SIDE

C-117

41

42

43

44

45

46

47

48

49

50

BF

MULTI-CENTER DISPLAY

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CHASSIS ELECTRICAL

54A-286

STEP 3. Check the wiring harness between radio, CD 
player and CD changer connector C-117 (terminal 46, 42, 
41 and 47) and multi-center display unit (middle grade 
type) connector C-05 (terminal 7, 8, 9 and 10).
Q: Is the wiring harness between radio, CD player and CD 

changer connector C-117 (terminal 46, 42, 41 and 47) 
and multi-center display unit (middle grade type) 
connector C-05 (terminal 7, 8, 9 and 10) in good 
condition?
YES : Go to Step 4.
NO :  Repair the wiring harness and then go to step 1.

STEP 4.Using the oscilloscope, check the M BUS line.
(1) Connect the multi-center display unit (middle grade type) 

connector C-05 and radio, CD player and CD changer 
connector C-117.

(2) Connect the oscilloscope probe to terminal 10 of the 

multi-center display unit (middle grade type) connector by 
backprobing.

(3) Turn the ignition switch to “ACC” position.
(4) Operate each of the radio, CD player and CD changer 

switches.

Q: Is a wave pattern displayed?

YES : Intermittent malfunction (Refer to GROUP 00, How to 

Use Troubleshooting/Inspection Service Points-How 
to Cope with Intermittent malfunction 

P.00-6

.

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

and then go to Step 6. 

STEP 5. Retest the system
Confirm that the audio operation screen is displayed normally.
Q: Is the check result satisfactory?

YES : The procedure is complete.
NO :  Replace radio, CD player and CD changer and then 

go to step 6.

AC305234

CONNECTORS: C-05, C-117

C-05 (B)

C-117

HARNESS SIDE

C-05

HARNESS SIDE

C-117

41

42

43

44

45

46

47

48

49

50

BF

AC209711AB

C-06 HARNESS CONNETOR:
HARNESS SIDE

OSCILLOSCOPE 
PROBE

OSCILLOSCOPE