Mitsubishi 380. Manual — part 687

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-158

(2) Measure the resistance at connector A-02, and use special

tool Inspection Check Harness (MB991219) to probe the
wiring harness-side connector.

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 "LOCK" (OFF) position.

NOTE: When diagnosing CAN BUS on vehicles with
manual transmission (M/T) disregard A/T-ECU and it’s
wiring circuits and measure between ABS-ECU and
ENGINE-ECU only.

CAUTION

Disconnect the negative battery terminal. For details refer
to

P.54C-4

.

(4) Disconnect the negative battery terminal.
(5) Measure the resistance between connector A-02 terminal

25 (using inspection test harness MB991219) and body
ground.

OK: 1 k

Ω or more

Q: Does the resistance measure 1 k

Ω or more?

YES : If the resistance measures 1 k

Ω or more, diagnose

CAN bus lines thoroughly by referring to

P.54C-323

.

NO : If the resistance measures less than 1 k

Ω, replace the

ABS-ECU.

16DB492A

TEST HARNESS

(MB991219)

CONNECTOR: A-02

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-159

STEP 24. Check the CAN_H line (communication line only)
between the ENGINE- ECU connector and A/T-ECU
connector for short to ground. Measure the resistance at
ENGINE- ECU connector B-21.

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 resistance at the harness
side of ENGINE- ECU connector B-21.

(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.

NOTE: When diagnosing CAN BUS on vehicles with
manual transmission (M/T) disregard A/T-ECU and it’s
wiring circuits and measure between ABS-ECU and
ENGINE-ECU only.

16DB480A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

A/T

CONTROL

UNIT

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-160

(4) Measure the resistance between ENGINE- ECU connector

terminal 64 and body ground.

OK: 1 k

Ω or more

CAUTION

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

P.54C-5

.

NOTE: When diagnosing CAN BUS on vehicles with
manual transmission (M/T) disregard A/T-ECU and it’s
wiring circuits and measure between ABS-ECU and
ENGINE-ECU only.

Q: Does the resistance measure 1 k

Ω or more?

YES : If the resistance measures 1 k

Ω or more, go to Step

25 .

NO : If the resistance measures less than 1 k

Ω, repair the

wiring harness between ENGINE- ECU B-21
connector and A/T-ECU B-19 connector.

STEP 25. Check the CAN_H line inside the A/T-ECU for
short to ground. Measure the resistance at A/T-ECU
connector B-19.

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.

16DB493A

HARNESS SIDE: B-21

TEST
HARNESS

16DB480A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

A/T

CONTROL

UNIT

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-161

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

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

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

NOTE: When diagnosing CAN BUS on vehicles with
manual transmission (M/T) disregard A/T-ECU and it’s
wiring circuits and measure between ABS-ECU and
ENGINE-ECU only.

CAUTION

Disconnect the negative battery terminal. For details refer
to

P.54C-4

.

(4) Disconnect the negative battery terminal.
(5) Measure the resistance between special tool MB992045

(A/T check harness) connector terminal 13 and body
ground.

OK: 1 k

Ω or more

Q: Does the resistance measure 1 k

Ω or more?

YES : If the resistance measures 1 k

Ω or more, diagnose

CAN bus lines thoroughly by referring to

P.54C-323

.

NO : If the resistance measures less than 1 k

Ω, replace the

A/T-ECU.

STEP 26. Check intermediate connector C-29 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.

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: Is intermediate connector C-29 in good condition?

YES : Go to Step 27.
NO : Repair the damaged parts.

16DB494A

TEST
HARNESS

SPECIAL TOOL

MB992045

A/T-

ECU

MEASURE AT THIS CONNECTOR

SPECIAL TOOL MB992045

CONNECTOR

52DB014A

CONNECTOR: C-29