Mitsubishi Galant 9G. Manual — part 1254

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-120

.

TROUBLE JUDGMENT

A short to the power supply may be present when the
voltage between the CAN bus line (CAN_L or
CAN_H) and body ground is more than 4.0 V. In this
condition, an abnormal voltage may be measured at
CAN_L and CAN_H lines.

.

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 may be defective

• 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

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-121

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB991970: ABS Check Harness

STEP 1. Check powertrain control module connector B-19,

combination meter connector C-101 and data link

connector C-125 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: Are powertrain control module connector B-19,

combination meter connector C-101 and data link

connector C-125 in good condition?
YES : . Go to Step 2.

NO : Repair the damaged parts.

AC306248AD

B-19 (B)

CONNECTOR: B-19

PCM

AIR
CLEANER

HARNESS SIDE

AC305232

CONNECTORS: C-101, C-125

AH

C-101

C-125

C-125 (B)

C-101 HARNESS SIDE

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-122

STEP 2. Check the CAN_H-side bus line (communication

line including ECUs) for a short to the power supply.

Measure the voltage at data link connector C-125.

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 powertrain control module connector B-19 and

combination meter connector C-101, and measure the
voltage at the harness side of data link connector C-125.

(2) Turn the ignition switch to the "ON" position.

AC306248AD

B-19 (B)

CONNECTOR: B-19

PCM

AIR
CLEANER

HARNESS SIDE

AC305232

CONNECTORS: C-101, C-125

AH

C-101

C-125

C-125 (B)

C-101 HARNESS SIDE

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-123

(3) Measure the voltage between data link connector terminal 6

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, go to Step 3.
NO : If the voltage measures more than 4.0 V, go to Step 4.

AC209365

HARNESS SIDE: C-125

TEST
HARNESS

FN

Y

8

16

15

7

5

1314

6

12

4

2

1011

3

9

1