Mitsubishi Evolution X. Manual — part 112

54C-1

GROUP 54C

CONTROLLER

AREA NETWORK

(CAN)

CONTENTS

GENERAL INFORMATION . . . . . . . .

54C-2

STRUCTURE . . . . . . . . . . . . . . . . . . .

54C-3

SYSTEM OPERATION. . . . . . . . . . . .

54C-5

SELF-DIAGNOSIS . . . . . . . . . . . . . . .

54C-8

CAN BUS DIAGNOSTICS . . . . . . . . .

54C-8

GENERAL INFORMATION

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-2

GENERAL INFORMATION

M2542000100308

CAN, an abbreviation for Controller Area Network, is
an ISO-certified international standard for a serial
multiplex communication protocol

*

. A communication

circuit employing the CAN protocol connects each
ECU, and sensor data can be shared among, which
enables more reduction in wiring.
NOTE:

*

: The regulations have been decided in

detail, from software matters such as the necessary
transmission rate for communication, the system,
data format, and communication timing control
method to hardware matters such as the harness
type and length and the resistance values.

CAN offers the following advantages.

• Transmission rates are much faster than those in

conventional communication (up to 1 Mbps),
allowing much more data to be sent.

• It is exceptionally immune to noise, and the data

obtained from each error detection device is more
reliable.

• Each ECU connected via the CAN communicates

independently, therefore if the ECU enters dam-
aged mode, communications can be continued in
some cases.

STRUCTURE

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-3

STRUCTURE

M2542000200695

• A gateway function has been integrated to

ETACS-ECU as the network central ECU. (Refer
to GROUP 54A, ETACS-ECU

P.54A-39

.)

• The CAN system consists of the following three

networks: CAN-B (middle-speed body network),
CAN-C (high-speed power train network), and the
diagnosis CAN-C (diagnosis exclusive network).
Each ECU is connected to one of the networks
depending on its functions.

• The CAN bus line consists of two lines, CAN_L

and CAN_H (CAN Low and CAN High, respec-
tively), as well as two terminal resistors (A
twisted-pair cable, highly resistant to noise, is
used for the communications line).

• The CAN bus line connecting two dominant

ECUs is the main bus line, and the CAN bus line
connecting each ECU is the sub-bus line.

AC709105

ECM

SRS-ECU

A/C-ECU

CAN box
unit

Satellite
radio tuner

Hands free
module

Radio and
CD player or
CD changer

Combination
meter

WCM OR
KOS-ECU

Scan tool

Data link
connector

ETACS-ECU

ASC-ECU

CAN_H

CAN_L

Main bus line

CAN_H

CAN_L

CAN_H

CAN_L

CAN-C

CAN-B

Diagnosis CAN-C

AB

Terminal resistor

Terminal
resistor

: Indicates main bus line

: Indicates sub bus line

Occupant
classification-
ECU

Main bus line

TC-SST-
ECU

Shift lever

S-AWC-
ECU

Steering
wheel
sensor

STRUCTURE

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-4

• With CAN-C, the terminal resistors are incorpo-

rated in ECU. Resistors with approximately 120
ohms is used for the dominant ECU, and that with
3.0 kiloohms is used for the non-dominant ECU.
NOTE:

.

•

Dominant ECU: ETACS-ECU and engine
ECU

•

Non-dominant ECU: ECU and sensor on
CAN-C network, excluding ETACS-ECU and
engine ECU

• To the CAN bus line, ECU, sensor, and data link

connector are connected as follows for each net-
work.
CAN-B

• Wireless control module (WCM) <vehicles

without KOS>

• KOS-ECU <vehicles with KOS>

• SRS-ECU

• Occupant classification-ECU

• A/C-ECU

• Radio and CD player or CD changer <vehi-

cles without Mitsubishi Multi-Communication
System (MMCS)>

• CAN box unit <vehicles with Mitsubishi

Multi-Communication System (MMCS)>

• Hands free module <vehicles with hands-free

system>

• Satellite radio tuner <vehicles with satellite

radio>

• Combination meter

CAN-C

• ASC-ECU

• TC-SST-ECU <TC-SST>

• Shift lever <TC-SST>

• S-AWC-ECU

• Steering wheel sensor

• Engine control module (ECM)

Diagnosis CAN-C

• Data link connector