Mitsubishi 380. Manual — part 666

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-75

(1) Disconnect A/T-ECU connector B-19 and ABS-ECU

connector A-02, and measure the voltage at the harness
side of A/T-ECU connector B-19.

(2) Turn the ignition switch to the "ON" position.
NOTE: When diagnosing CAN BUS on vehicles with
manual transmission (M/T) please disregard A/T ECU and
its circuits.

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-76

(3) Measure the voltage between A/T-ECU connector terminal

14 and body ground.

OK: 1.0 V or less

CAUTION

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

P.54C-5

.

Q: Does the voltage measure 1.0 V or less?

YES : If the voltage measures 1.0 V or less, go to Step 45.
NO : If the voltage measures more than 1.0 V, repair the

wiring harness between ENGINE-ECU connector and
ABS-ECU connector.

STEP 45. Check the CAN_L line inside the ABS-ECU for a
short to the power supply. Measure the voltage at
ABS-ECU connector A-02 for loose, corroded or damaged
terminals, or terminals pushed back in the connector.

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.

16DB485A

B-19

TEST
HARNESS

16DB402A

A-02 (GR)

CONNECTOR: A-02

A-02 HARNESS CONNECTOR:

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-77

(2) Measure the voltage using special tool MB991219

(Inspection test harness), by inserting probe into the wiring
harness-side connector A-02.
NOTE: The special tool (Inspection test harness)
MB991219 for connector pin contact pressure should be
used. The test probe should never be forcibly inserted, as it
may cause a defective contact.

(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between connector A-02 terminal 14

and body ground, using inspection test harness
(MB991219).
NOTE: The special tool (Inspection test harness)
MB991219 for connector pin contact pressure should be
used. The test probe should never be forcibly inserted, as it
may cause a defective contact.

OK: 4.0 V or less

Q: Does the voltage measure 4.0 V or less?

YES : If the voltage measures 4.0 V or less, diagnose CAN

bus lines thoroughly by referring to

P.54C-323

.

NO : If the voltage measures more than 4.0 V, replace the

ABS-ECU.

16DB486A

TEST
HARNESS

CONNECTOR: A-02

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-78

STEP 46. Check the CAN_L line (communication line only)

between the ENGINE-ECU connector and A/T-ECU

connector for a short to the power supply. Measure voltage

at ENGINE-ECU connector B-21.

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

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 ENGINE-ECU connector B-21 and A/T-ECU

connector B-19, and measure the voltage at the harness
side of ENGINE-ECU connector B-21.

(2) Turn the ignition switch to the "ON" position.
NOTE: When diagnosing CAN BUS on vehicles with
manual transmission (M/T) please disregard A/T ECU and
its circuits.

16DB480A

COVER

ENGINE
CONTROL
UNIT

AIR
CLEANER

A/T
CONTROL
UNIT

16DB400A

COVER

ENGINE
CONTROL
UNIT

AIR
CLEANER