Mitsubishi Galant (2004+). Manual — part 401

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-215

DIAGNOSTIC ITEM 5: Diagnose shorts in the ground to CAN bus line <Vehicles with ABS and vehicles
without 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

NOTE

: MANUAL AIR CONDITIONING SYSTEM <LOW>
: MANUAL AIR CONDITIONING SYSTEM<MIDDLE>
OR AUTOMATIC AIR CONDITIONING SYSTEM

ABS-ECU

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-216

.

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 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 ABS-ECU may be defective

• The powertrain control module may be defective

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB991970: ABS Check Harness

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

AC305233 AU

CONNECTORS: C-10, C-15, C-22, C-121

C-121 (Y)

C-22 (Y)

C-10 (B)

C-15 (B)

AC305413

C-218 (GR)

CONNECTOR: C-218

AJ

JUNCTION BLOCK
(REAR VIEW)

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-217

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-218

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