Mitsubishi 380. Manual - part 650

EXPLANATION ABOUT THE DIAGNOSTIC TOOL (MUT-III) CAN BUS DIAGNOSTICS

CONTROLLER AREA NETWORK (CAN)

54C-11

NOTE: If you pinpoint trouble spot according to 
DTC code, you should use time-out DTC code. 
DTC code related to failure information is set 
when the data to be set contains an error, so CAN 
bus line itself is probably normal.

NOTE: Time-out DTC codes are stored in each 
ECU memory individually. Therefore, it is possible 
that these DTC codes have not been set simulta-
neously. If the trouble spot cannot be found when 
you diagnose by judging from multiple DTC 
codes, check the communication lines between 
each ECU.

DTC CODE TO 
BE SET

POSSIBLE 
TROUBLE 
SPOT

LOGIC FOR DETERMINING TROUBLE SPOT

Time-out DTC 
code 
associated with 
ECU D is stored 
in ECU A, ECU 
B and ECU C

Trouble in 
CAN bus line 
(e) and power 
supply system 
to ECU D

When time-out DTC code 
associated with ECU D is stored 
in ECU A, B and C, or time-out 
DTC code associated with ECUs 
A, B and C is stored in ECU D, or 
"bus off" DTC code is stored in 
ECU D, CAN bus line (e) is 
suspected. When DTC code is 
not stored in ECU D, the power 
supply to ECU D is suspected.

Time-out DTC 
code 
associated with 
ECUs A, B and 
C is stored in 
ECU D

"Bus off" DTC 
code is stored 
in ECU D

AC204742 BD

DATA LINK 

CONNECTOR

ECU B

ECU C

ECU D

ECU A

(a)

(b)

(c)

(d)

(e)

(f)

(g)

EXPLANATION ABOUT THE DIAGNOSTIC TOOL (MUT-III) CAN BUS DIAGNOSTICS

CONTROLLER AREA NETWORK (CAN)

54C-12

Time-out DTC 
code 
associated with 
ECU A is stored 
in ECUs B, C 
and D

Trouble in 
CAN bus line 
(a) and power 
supply system 
to ECU A

When time-out DTC code 
associated with ECU A is stored 
in ECUs B, C and D, or time-out 
DTC code associated with ECUs 
B, C and D is stored in ECU A, or 
"bus off" DTC code is stored in 
ECU A, CAN bus line (a) or (c) is 
suspected. When DTC code is 
not stored in ECU A, the power 
supply to ECU A is suspected.

Time-out DTC 
code 
associated with 
ECUs B, C and 
D is stored in 
ECU A

"Bus off" DTC 
code is stored 
in ECU A

Time-out DTC 
codes 
associated with 
ECUs C and D 
are stored in 
ECU A and 
ECU B

Trouble in 
CAN bus line 
(d)

If time-out DTC codes associated 
with ECUs C and D are stored in 
ECUs A and B, or time-out codes 
associated with ECUs A and B 
are stored in ECUs C and D, CAN 
bus line (d) is suspected. CAN 
bus line (g) or (e) and power 
supply systems to ECU C or D 
are also suspected as second 
cause.

Time-out DTC 
codes 
associated with 
ECUs A and B 
are stored in 
ECU C and 
ECU D

DTC CODE TO 
BE SET

POSSIBLE 
TROUBLE 
SPOT

LOGIC FOR DETERMINING TROUBLE SPOT

AC204742 BE

DATA LINK 

CONNECTOR

ECU B

ECU C

ECU D

ECU A

(a)

(b)

(c)

(d)

(e)

(f)

(g)

AC204742 BF

DATA LINK 

CONNECTOR

ECU B

ECU C

ECU D

ECU A

(a)

(b)

(c)

(d)

(e)

(f)

(g)

AC204742BG

DATA LINK 

CONNECTOR

ECU B

ECU C

ECU D

ECU A

(a)

(b)

(c)

(d)

(e)

(f)

(g)

DIAGNOSTIC TROUBLE CODE DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-13

DIAGNOSTIC TROUBLE CODE DIAGNOSIS

M1548304500025

ON-BOARD DIAGNOSTICS

The CAN is a communication method which the 
ECUs use in order to communicate each other. The 
CAN-related diagnostic trouble codes will be stored 
in the following ECUs, which use the CAN communi-
cation.

• Engine ECU

• A/T ECU

• ABS-ECU

• ETACS-ECU

• A/C-ECU

• SRS-ECU

• Combination meter

• Multi-center display 

HOW TO CONNECT THE DIAGNOSTIC TOOL 
(MUT-III)

Required Special Tools:

•  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

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. Ensure that the ignition switch is at the "LOCK" (OFF) 

position.

2. Start up the personal computer.
3. Connect special tool MB991827 to special tool MB991824 

and the personal computer.

4. Connect special tool MB991910 to special tool MB991824.
5. Connect special tool MB991910 to the data link connector.
6. Turn the power switch of special tool MB991824 to the "ON" 

position.
NOTE: When special tool MB991824 is energised, special 
tool MB991824 indicator lamp will be illuminated in a green 
color.

7. Start the MUT-III system on the personal computer.
NOTE: Disconnecting diagnostic tool MB991958 is the reverse 
of the connecting sequence, making sure that the ignition 
switch is at the "LOCK" (OFF) position.

HOW TO DIAGNOSE THE CAN BUS LINE

Required Special Tools:

•  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

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

DIAGNOSTIC TROUBLE CODE DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-14

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 to the data link 

connector.

2. Turn the ignition switch to the "ON" position.
3. Select "CAN bus diagnosis" from the start-up screen.
4. When the vehicle information is displayed, confirm that it 

matches the vehicle whose CAN bus lines will be 
diagnosed.

• If they match, go to step 8.

• If not, go to step 5.

5. Select the "view vehicle information" button.
6. Enter the vehicle information and select the "OK" button.
7. When the vehicle information is displayed, confirm again 

that it matches the vehicle whose CAN bus lines will be 
diagnosed.

• If they match, go to step 8.

• If not, go to step 5.

8. Select the "OK" button.
9. When the optional equipment screen is displayed, choose 

the one which the vehicle is fitted with, and then select the 
"OK" button.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827