Mitsubishi Galant 9G. Manual - part 1288

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-256

.

TROUBLE JUDGMENT

A short to ground may be present when the voltage 
between the CAN bus line (CAN_L or CAN_H) and 
body ground is less than 1.0 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 an 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 multi-center display unit (middle-grade type) 

may be defective

• The SRS-ECU 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-257

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-258

STEP 2. Check the CAN_H-side bus line (communication 
line including ECUs) for short to ground. Measure the 
resistance 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 
resistance at the harness side of data link connector C-125.

(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.

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-259

(4) Measure the resistance between data link connector 

terminal 6 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, go to Step 3   

.

NO :  If the resistance measures less than 1 k

Ω, go to Step 

4.

AC209364

Y

8

16

15

7

5

1314

6

12

4

2

1011

3

9

1

AC209364

AC209364

AC209364

AC209364

AC209364HT

HARNESS SIDE: C-125

TEST 
HARNESS