Mitsubishi Lancer Evolution X. Manual - part 46

DIAGNOSIS

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CONTROLLER AREA NETWORK (CAN)

54C-209

STEP 3. Using scan tool MB991958, diagnose the CAN bus 
line. (trouble symptom check)

CAUTION

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

P.54C-7

.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.

(3) Diagnose CAN bus lines, and check if the scan tool 

MB991958 screen is as shown in the figure.

OK: The display of the scan tool MB991958 is as 
shown in the figure.

Q: Does scan tool MB991958 screen correspond to the 

illustration?
YES : The trouble can be an intermittent malfunction (Refer 

to GROUP 00, How to use 
Troubleshooting/inspection Service Points − How to 

Cope with Intermittent Malfunction 

P.00-15

).

NO :  Replace the ETACS-ECU.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

AC709542 AB

: Red section on screen

M.U.T.

J/C (3)

SAS

J/C (2)

KOS/WCM

SRS

A/C

AUDIO

MMCS

Sat Radio

HFM

OCM

METER

ASC

ENGINE

J/C (1)

ETACS

<M/T>

S-AWC

AC709543 AB

: Red section on screen

M.U.T.

J/C (3)

SAS

J/C (2)

KOS/WCM

SRS

A/C

AUDIO

MMCS

Sat Radio

HFM

OCM

METER

ASC

LEVER

ENGINE

J/C (1)

ETACS

<TC-SST>

S-AWC

TC-SST

J/C (4)

DIAGNOSIS

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CONTROLLER AREA NETWORK (CAN)

54C-210

DIAGNOSTIC ITEM 27: Short to power supply or ground, open circuit or line-to-line short in the 
CAN-B bus lines.

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 connected to the CAN bus line may be damaged.

CAN-B Communication Circuit

ETACS-ECU

INTERFACE 
CIRCUIT

CAN DRIVE 
CIRCUIT

A/C-ECU

COMBINATION 
METER

SRS-ECU

WIRELESS 
CONTROL 
MODULE

KOS-ECU

NOTE

VEHICLES WITH WCM
VEHICLES WITH KOS

CAN DRIVE 
CIRCUIT

CAN DRIVE 
CIRCUIT

CAN DRIVE 
CIRCUIT

JOINT CONNECTOR 
(CAN1)

DIAGNOSIS

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CONTROLLER AREA NETWORK (CAN)

54C-211

CAN-B Communication Circuit

ETACS-ECU

INTERFACE 
CIRCUIT

INTERFACE 
CIRCUIT

CAN DRIVE 
CIRCUIT

HANDS FREE 
MODULE

OCCUPANT 
CLASSIFICATION-
ECU

SATELLITE 
RADIO TUNER

RADIO AND CD
PLAYER

NOTE

VEHICLES WITHOUT MITSUBISHI MULTI-COMMUNICATION SYSTEM (MMCS)
VEHICLES WITH MITSUBISHI MULTI-COMMUNICATION SYSTEM (MMCS)

CAN 
TRANSCEIVER 
CIRCUIT

CAN BOX UNIT

JOINT CONNECTOR 
(CAN1)

FRONT SEAT 
ASSEMBLY (LH)

DIAGNOSIS

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CONTROLLER AREA NETWORK (CAN)

54C-212

.

FUNCTION

If a short to power supply or ground, open circuit or 
line-to-line short is present at either CAN_H or 
CAN_L side on the CAN-B lines, this diagnosis result 
will be set.

.

TROUBLE JUDGMENT CONDITIONS

When CAN-B lines communication is normal, and 
diagnostic trouble code U0019 is set, the 
ETACS-ECU determines that there is a failure.

.

TROUBLESHOOTING HINTS

• Malfunction of the connector (short to power sup-

ply or ground in connector or improperly con-
nected)

• Malfunction of the wiring harness (short to power 

supply or ground, open circuit or line-to-line short 
in CAN bus lines)

• Faulty ECU(s) (internal short to power supply or 

ground)

AC608145

AO

Connectors: C-04, C-06, C-09, C-31, C-122

C-06

C-31

C-04

C-09

C-122 (Y)

AC608146

AE

C-17

C-108

Connectors: C-17, C-20, C-104, C-108, C-110

C-20 (B)

C-104

C-110

AC708950CF

C-05

C-41

C-105

Connectors: C-05, C-41, C-105

AC708951CF

Connectors: C-07, C-11, C-15, C-18, C-22, 
C-37, C-107

C-07

C-15

C-18

C-22 (B)

C-11

C-37 (Y)

C-107

AC708972AY

Connector: C-301

ETACS-ECU

AC708954 AV

Connectors: D-39, D-39-2

D-39, 
D-39-2