Mitsubishi 380. Manual - part 680

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-131

(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-132

STEP 52. 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-

• Refer to configuration diagrams GROUP-

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

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-133

(3) Measure the voltage between ENGINE-ECU connector

terminal 86 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 53.
NO : If the voltage measures more than 1.0 V, repair the

wiring harness between ENGINE-ECU connector and
A/T-ECU connector.

STEP 53. Check the CAN_L line inside the A/T-ECU for a
short to the power supply. Measure the voltage at A/T-ECU
connector B-19 for loose, corroded or damaged terminals,
or terminals pushed back in the connector.

• Refer to circuit diagrams GROUP-

• Refer to configuration diagrams GROUP-

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 A/T-ECU connector B-19.
NOTE: When diagnosing CAN BUS on vehicles with
manual transmission (M/T) please disregard A/T ECU and
its circuits.

16DB487A

HARNESS SIDE: B-21

TEST
HARNESS

16DB480A

COVER

ENGINE
CONTROL
UNIT

AIR
CLEANER

A/T
CONTROL
UNIT

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-134

(2) Connect special tool MB992045 (A/T check harness) to the

A/T-ECU and the wiring harness, and measure the voltage
at special tool MB992045 (A/T check harness).

(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between special tool MB992045 (A/T

check harness) connector terminal 14 and body ground.

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

A/T-ECU.

NOTE: When diagnosing CAN BUS on vehicles with
manual transmission (M/T) please disregard A/T ECU and
its circuits.

16DB488A

TEST
HARNESS

SPECIAL TOOL
MB992045

A/T-
ECU

MEASURE AT THIS CONNECTOR

SPECIAL TOOL MB992045
CONNECTOR

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