Mitsubishi 380. Manual — part 741

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-375

STEP 2. 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, 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.

16DB402A

A-02 (GR)

CONNECTOR: A-02

A-02 HARNESS CONNECTOR:

16DB480A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

A/T

CONTROL

UNIT

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-376

(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 3.

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

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-377

STEP 3. Check the CAN bus lines inside the ABS-ECU.
Measure the resistance at ABS-ECU connector A-02.

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 measure the

resistance at the component side of ABS-ECU connector
A-02.

(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.
(4) Measure the resistance between ABS-ECU connector A-02

terminals 14 and 15.

OK: 2 ohms or less

(5) Measure the resistance between ABS-ECU connector

terminals 25 and 26.

OK: 2 ohms or less

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, power

supply to the A/T-ECU may be suspected. Diagnose
the automatic transmission. Refer to GROUP 13A,
MPI diagnosis

P.13A-571

<3.8L engine>.

NO : If either of the resistances measures more than 2

ohms or all the resistances measure more than 2
ohms, replace the ABS-ECU.

16DB515A

COMPONENT SIDE: A-02

TEST
HARNESS

TEST
HARNESS

16DB516A

COMPONENT SIDE: A-02

TEST
HARNESS

TEST
HARNESS

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-378

DIAGNOSTIC ITEM 11: Diagnose the lines between CAN main bus line and the ABS-ECU.

CAUTION

When servicing a CAN bus line, ground yourself
by touching a metal object such as an unpainted
water pipe. If you fail to do so, a component con-
nected to the CAN bus line may be damaged.

.

TROUBLE JUDGMENT

If the MUT-III cannot received signals from
ABS-ECU, CAN bus line connector(s) are broken or
an open circuit has occurred.

.

COMMENTS ON TROUBLE SYMPTOM

The wiring harness wire or connectors may have
loose, corroded, or damage terminals, or terminals
pushed back in the connector, or the ABS-ECU may
be defective.

.

TROUBLESHOOTING HINTS

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

• The wiring harness or connectors may have

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

• The ABS-ECU may be defective

16DB402A

A-02 (GR)

CONNECTOR: A-02

A-02 HARNESS CONNECTOR:

16DB408A

CONNECTOR: C-02

52DB014A

CONNECTOR: C-29