Mitsubishi Lancer (4A9 engine). Manual — part 274

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-120

STEP 22. M.U.T.-III CAN bus diagnostics
(checking the combination meter for internal
failure)

CAUTION

Strictly observe the specified wiring harness
repair procedure. For details refer to .
Disconnect C-01 combination meter connector, and
diagnose the CAN bus line.

ACB01921AC

M.U.T.

JC

JC

SAS

AT/

CVT

EPS

ENGINE

ABS/

ASC

: Red section on screen

AS&G

ETACS

JC

KOS/
WCM

SRS

A/C

AUDIO

METER

MMCS

Levelling

Cor ner

OK: The display of the M.U.T.-III is as shown
in the figure.

Q: Does M.U.T.-III screen correspond to the

illustration?
YES :

Repair the wiring harness between C-01

combination meter connector and C-04 joint
connector (CAN1).

NO :

Check the combination meter connector,
and repair if necessary. If the combination
meter connector is in good condition,
replace the combination meter.

STEP 23. M.U.T.-III CAN bus diagnostics
(checking the WCM for internal failure)

CAUTION

Strictly observe the specified wiring harness
repair procedure. For details refer to .
Disconnect C-06 WCM connector, and diagnose the
CAN bus line.

ACB01921AC

M.U.T.

JC

JC

SAS

AT/

CVT

EPS

ENGINE

ABS/

ASC

: Red section on screen

AS&G

ETACS

JC

KOS/
WCM

SRS

A/C

AUDIO

METER

MMCS

Levelling

Cor ner

OK: The display of the M.U.T.-III is as shown
in the figure.

Q: Does M.U.T.-III screen correspond to the

illustration?
YES :

Repair the wiring harness between C-06

WCM connector and C-04 joint connector
(CAN1).

NO :

Check the WCM connector, and repair if
necessary. If the WCM connector is in good
condition, replace the WCM.

STEP 24. M.U.T.-III CAN bus diagnostics
(checking the KOS-ECU for internal failure)

CAUTION

Strictly observe the specified wiring harness
repair procedure. For details refer to .
Disconnect C-23 KOS-ECU connector, and diagnose
the CAN bus line.

ACB01921AC

M.U.T.

JC

JC

SAS

AT/

CVT

EPS

ENGINE

ABS/

ASC

: Red section on screen

AS&G

ETACS

JC

KOS/
WCM

SRS

A/C

AUDIO

METER

MMCS

Levelling

Cor ner

OK: The display of the M.U.T.-III is as shown
in the figure.

Q: Does M.U.T.-III screen correspond to the

illustration?

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-121

YES :

Repair the wiring harness between C-23

KOS-ECU connector and C-04 joint
connector (CAN1).

NO :

Check the KOS-ECU connector, and repair
if necessary. If the KOS-ECU connector is in
good condition, replace the KOS-ECU.

STEP 25. M.U.T.-III CAN bus diagnostics
(checking the radio and CD player for internal
failure)

CAUTION

Strictly observe the specified wiring harness
repair procedure. For details refer to .
Disconnect C-103 radio and CD player connector,
and diagnose the CAN bus line.

ACB01921AC

M.U.T.

JC

JC

SAS

AT/

CVT

EPS

ENGINE

ABS/

ASC

: Red section on screen

AS&G

ETACS

JC

KOS/
WCM

SRS

A/C

AUDIO

METER

MMCS

Levelling

Cor ner

OK: The display of the M.U.T.-III is as shown
in the figure.

Q: Does M.U.T.-III screen correspond to the

illustration?
YES :

Repair the wiring harness between C-103

radio and CD player connector and C-04
joint connector (CAN1).

NO :

Check the radio and CD player connector,
and repair if necessary. If the radio and CD
player connector is in good condition,
replace the radio and CD player.

STEP 26. M.U.T.-III CAN bus diagnostics
(checking the CAN box unit for internal failure)

CAUTION

Strictly observe the specified wiring harness
repair procedure. For details refer to .
Disconnect C-54 CAN box unit connector, and diag-
nose the CAN bus line.

ACB01921AC

M.U.T.

JC

JC

SAS

AT/

CVT

EPS

ENGINE

ABS/

ASC

: Red section on screen

AS&G

ETACS

JC

KOS/
WCM

SRS

A/C

AUDIO

METER

MMCS

Levelling

Cor ner

OK: The display of the M.U.T.-III is as shown
in the figure.

Q: Does M.U.T.-III screen correspond to the

illustration?
YES :

Repair the wiring harness between C-54

CAN box unit connector and C-04 joint
connector (CAN1).

NO :

Check the CAN box unit connector, and
repair if necessary. If the CAN box unit
connector is in good condition, replace the
CAN box unit.

STEP 27. Trouble symptom check
Diagnose the CAN bus line, and check that normal
condition is displayed.

Q: Is the check result normal?

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 ).

NO :

Check the ETACS-ECU connector, and
repair if necessary. If the ETACS-ECU
connector is in good condition, replace the
ETACS-ECU.

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-122

Diagnosis Item 24: Diagnose the ETACS-ECU, joint connector (CAN1) or lines between ETACS-ECU
and joint connector (CAN1)

CAUTION

When servicing a CAN bus line, earth yourself by touching a metal object such as an unpainted water
pipe. If you fail to do, a component connected to the CAN bus line may be broken.

CAN-B Communication Circuit

ETACS-ECU

INTERFACE
CIRCUIT

CAN DRIVE
CIRCUIT

SRS-ECU

CPU

WCM

CAN BOX UNIT

KOS-ECU

CAN
TRANSCEIVER
CIRCUIT

CAN DRIVE
CIRCUIT

CAN DRIVE
CIRCUIT

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple SI : Silver

RADIO AND
CD PLAYER

CAN
TRANSCEIVER
CIRCUIT

INTERFACE
CIRCUIT

VEHICLES WITHOUT A/C

:

VEHICLES WITH A/C

:

VEHICLES WITH KOS

:

NOTE

VEHICLES WITH WCM

:

VEHICLES WITH RADIO AND CD PLAYER

:

VEHICLES WITHOUT AUDIO

:

VEHICLES WITH MMCS

:

COMBINATION
METER

HEATER CONTROL
PANEL
A/C-ECU

SPARE
CONNECTOR
(FOR AUDIO)

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-123