Mitsubishi Galant 9G. Manual — part 1314

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-360

DIAGNOSTIC ITEM 9: Diagnose shorts between CAN_L and H lines <Vehicles with ABS and vehicles
with multi-center display (middle-grade type)>

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.

DATA LINK
CONNECTOR

ETACS-ECU

POWERTRAIN
CONTROL
MODULE

JOINT
CONNECTOR (3)

COMBINATION
METER

A/C-ECU

SRS-ECU

ABS-ECU

MULTI CENTER
DISPLAY UNIT

DIAGNOSIS

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CONTROLLER AREA NETWORK (CAN)

54C-361

.

TROUBLE JUDGMENT

Short circuit may be present between the CAN_L
and H lines when the resistance between the CAN
bus lines (CAN_L and H lines) is less than 2 ohms.

.

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 a ECU may be
defective.

.

TROUBLESHOOTING HINTS

• The wiring harness or connectors may have

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

• The ETACS-ECU

• The combination meter may be defective

• The A/C-ECU may be defective

• The SRS-ECU may be defective

• The multi-center display unit (middle-grade type)

may be defective

• The ABS-ECU may be defective

• The powertrain control module may be defective

AC305206

CONNECTOR: A-02

AR

A-02 (GR)

AC306248AB

B-19 (B)

CONNECTOR: B-19

AIR
CLEANER

PCM

AC305231BZ

C-101

C-125 (B)

C-29

C-02

CONNECTORS: C-02, C-29, C-101, C-125

AC305233AV

CONNECTORS: C-05, C-15, C-22, C-121

C-121 (Y)

C-22 (Y)

C-15 (B)

C-05 (B)

AC305413

C-218 (GR)

CONNECTOR: C-218

AJ

JUNCTION BLOCK
(REAR VIEW)

DIAGNOSIS

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CONTROLLER AREA NETWORK (CAN)

54C-362

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB991970: ABS Check Harness

STEP 1. 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 2.
NO : Repair the damaged parts.

AC305231AI

CONNECTOR: C-29

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-363

STEP 2. Check the lines between the CAN_L and H lines
(communication line including ECUs) of the front wiring
harness for a short circuit. Measure the resistance at
intermediate connector C-29.

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 intermediate connector C-29, and measure the

resistance at the male side (at front wiring harness side).

(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 intermediate connector

terminals 11 and 12.

OK: 120

± 20 Ω

Q: Does the resistance measure 120

± 20 Ω?

YES : If the resistance measures 120

± 20 Ω, go to Step 3.

NO : If the resistance does not measure 120

± 20 Ω, go to

Step 30 .

AC305231AI

CONNECTOR: C-29

AC204582

2 3

27

32

28

33

16

15

4 5

19

18

29

17

34

7 8

35

22

21

9 10

30

36

31

37

25

24

23

6

20

1

14

26

11

13

12

38

BX

TEST
HARNESS

TEST
HARNESS

MALE SIDE: C-29