Mitsubishi 380. Manual - part 735

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-351

STEP 21. Check ABS-ECU connector A-02, A/T-ECU 
connector B-19 and ENGINE-ECU connector B-21 for 
loose, corroded or damaged terminals, or terminals 
pushed back in the connector.

NOTE: when diagnosing CAN-BUS on vehicles with 
manual transmission (M/T), disregard A/T-ECU and it’s wir-
ing circuits and check between ABS-ECU and 
ENGINE-ECU only.

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

CAUTION

The strand end of the twisted wire should be within 10 cm 
(4 inches) from the connector. For details refer to 

P.54C-4

.

Q: Are ABS-ECU connector A-02, A/T-ECU connector B-19 

and ENGINE-ECU connector B-21 in good condition? 
YES : Go to Step 22.
NO :  Repair the damaged parts.

16DB402A

A-02 (GR)

CONNECTOR: A-02 

A-02 HARNESS CONNECTOR:

16DB407A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

A/T

CONTROL

UNIT

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-352

STEP 22. Using diagnostic tool MB991958, diagnose the 
CAN bus line (Disconnect ENGINE-ECU connector B-21, 
and check the ENGINE-ECU system).
(1) Disconnect ENGINE-ECU connector B-21.
(2) Turn the ignition switch to the "ON" position.

(3) Diagnose CAN bus lines, and check if the MUT-III screen is 

as shown in the illustration.

NOTE: When diagnosing CAN-BUS on vehi-

cles with manual transmission (M/T), disregard 
A/T-ECU and it’s wiring circuits and measure 
between ABS-ECU and ENGINE-ECU only.

NOTE: When diagnosing CAN-BUS on vehicles 
not equipped with a multi-centre display, disre-
gard the multi-centre display and it’s wiring cir-
cuits.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Connect ENGINE-ECU connector B-21.

Q: Does the MUT-III screen correspond to the illustration?

YES  : If the MUT-III screen corresponds to the illustration, 

go to Step 23 .

NO  :  If the MUT-III screen does not correspond to the 

illustration, go to Step 25.

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

16DB599A

: Red section on screen

ETACS

-ECU

AC-ECU

SRS-ECU

C.DISPLAY

MUT

J/C

ABS-ECU

METER

-ECU

ENGINE

ECU

A/T-ECU

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-353

STEP 23. Check the CAN bus lines between the ABS-ECU 
and the A/T-ECU. Measure the resistance between 
ABS-ECU connector A-02 and A/T-ECU connector B-19.

NOTE: when diagnosing CAN-BUS on vehicles with 
manual transmission (M/T), disregard A/T-ECU and it’s wir-
ing circuits and check between ABS-ECU and 
ENGINE-ECU only.

CAUTION

A digital multimeter should be used. For details refer to 

P.54C-4

.

CAUTION

The test wiring harness should be used. For details refer to 

P.54C-4

.

(1) Disconnect ABS-ECU connector A-02 and A/T-ECU 

connector B-19 (vehicles with A/T) or Engine-ECU 
connector B-21 (vehicles with M/T), and measure the 
resistance between each wiring harness side connector.

(2) Turn the ignition switch to the "LOCK" (OFF) position.

CAUTION

Disconnect the negative battery terminal. For details refer 
to 

P.54C-4

.

(3) Disconnect the negative battery terminal.

16DB480A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

A/T

CONTROL

UNIT

16DB402A

A-02 (GR)

CONNECTOR: A-02 

A-02 HARNESS CONNECTOR:

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-354

(4) Measure the resistance between ABS-ECU connector 

terminal 15 and A/T-ECU connector B-19 terminal 14.

OK: 2 ohms or less

(5) Measure the resistance between ABS-ECU connector 

terminal 26 and A/T-ECU connector B-19 terminal 13.

OK: 2 ohms or less

NOTE: when diagnosing CAN-BUS on vehicles with 
manual transmission (M/T), disregard A/T-ECU and it’s wir-
ing circuits and check between ABS-ECU and 
ENGINE-ECU only.

CAUTION

Strictly observe the specified wiring harness repair proce-
dure. For details refer to 

P.54C-5

.

Q: Do all the resistances measure 2 ohms or less?

YES  : If all the resistances measure 2 ohms or less, go to 

Step 24.

NO  :  If either of the resistances measures more than 2 

ohms or all the resistances measure more than 2 
ohms, repair the wiring harness between ABS-ECU 
connector and the A/T-ECU connector B-19. 

16DB507A

HARNESS SIDE: A-02

HARNESS SIDE: B-19

TEST 
HARNESS

TEST 
HARNESS

16DB508A

HARNESS SIDE: A-02

HARNESS SIDE: B-19

TEST 
HARNESS

TEST 
HARNESS