Mitsubishi Lancer (4A9 engine). Manual - part 278

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-136

STEP 32. Check the wiring harness between C-60 
heater control unit connector <vehicles without 
A/C> or C-15 A/C-ECU connector <vehicles with 
A/C> and C-04 joint connector (CAN1) for open 
circuit.
Disconnect heater control unit connector <vehicles 
without A/C> or A/C-ECU connector <vehicles with 
A/C> connector and joint connector (CAN1), and 
check the following wiring harness for open circuit.
(1) The wiring harness between C-60 heater control 

unit connector <vehicles without A/C> or C-15 A/
C-ECU connector <vehicles with A/C> terminal 
No.11 and C-04 joint connector (CAN1) terminal 
No.8.

OK: Continuity exists (2 

Ω or less)

(2) The wiring harness between C-60 heater control 

unit connector <vehicles without A/C> or C-15 A/
C-ECU connector <vehicles with A/C> terminal 
No.12 and C-04 joint connector (CAN1) terminal 
No.19.

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES : 

Go to Step 33.

NO  : 

Repair the wiring harness between C-60 
heater control unit connector <vehicles 
without A/C> or C-15 A/C-ECU connector 
<vehicles with A/C> and C-04 joint 
connector (CAN1).

STEP 33. Check the wiring harness between C-01 
combination meter connector and C-04 joint 
connector (CAN1) for open circuit.
Disconnect combination meter connector and joint 
connector (CAN1), and check the wiring harness for 
open circuit.
(1) The wiring harness between C-01 combination 

meter connector terminal No.14 and C-04 joint 
connector (CAN1) terminal No.9.

OK: Continuity exists (2 

Ω or less)

(2) The wiring harness between C-01 combination 

meter connector terminal No.15 and C-04 joint 
connector (CAN1) terminal No.20.

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES <vehicles without KOS> : 

Go to Step 34.

YES <vehicles with KOS> : 

Go to Step 35.

NO (the check result is not normal.) : 

Repair the 

wiring harness between C-01 combination 
meter connector and C-04 joint connector 
(CAN1).

STEP 34. Check the wiring harness between C-06 
WCM connector and C-04 joint connector (CAN1) 
for open circuit.
Disconnect WCM connector and joint connector 
(CAN1), and check the following wiring harness for 
open circuit.
(1) The wiring harness between C-06 WCM 

connector terminal No.11 and C-04 joint 
connector (CAN1) terminal No.7.

OK: Continuity exists (2 

Ω or less)

(2) The wiring harness between C-06 WCM 

connector terminal No.10 and C-04 joint 
connector (CAN1) terminal No.18.

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES <vehicles with radio and CD player> : 

Go to 

Step 36.

YES <vehicles with MMCS (vehicles for Russia)> : 

Go to Step 37.

YES <vehicles without MMCS and without radio 
and CD player> : 

Go to Step 38.

NO (the check result is not normal.) : 

Repair the 

wiring harness between C-06 WCM 
connector and C-04 joint connector (CAN1).

STEP 35. Check the wiring harness between C-23 
KOS-ECU connector and C-04 joint connector 
(CAN1) for open circuit.
Disconnect KOS-ECU connector and joint connector 
(CAN1), and check the following wiring harness for 
open circuit.
(1) The wiring harness between C-23 KOS-ECU 

connector terminal No.1 and C-04 joint connector 
(CAN1) terminal No.5.

OK: Continuity exists (2 

Ω or less)

(2) The wiring harness between C-23 KOS-ECU 

connector terminal No.2 and C-04 joint connector 
(CAN1) terminal No.16.

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES <vehicles with radio and CD player> : 

Go to 

Step 36.

YES <vehicles with MMCS (vehicles for Russia)> : 

Go to Step 37.

YES <vehicles without MMCS and without radio 
and CD player> : 

Go to Step 38.

NO (the check result is not normal.) : 

Repair the 

wiring harness between C-23 KOS-ECU 
connector and C-04 joint connector (CAN1).

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-137

STEP 36. Check the wiring harness between C-
103 radio and CD player connector and C-04 joint 
connector (CAN1) for open circuit.
Disconnect radio and CD player connector and joint 
connector (CAN1), and check the following wiring 
harness for open circuit.
(1) The wiring harness between C-103 radio and CD 

player connector terminal No.23 and C-04 joint 
connector (CAN1) terminal No.6.

OK: Continuity exists (2 

Ω or less)

(2) The wiring harness between C-103 radio and CD 

player connector terminal No.33 and C-04 joint 
connector (CAN1) terminal No.17.

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES  : 

Go to Step 39.

NO : 

Repair the wiring harness between C-103 
radio and CD player connector and C-04 
joint connector (CAN1)

STEP 37. Check the wiring harness between C-54 
CAN box unit connector and C-04 joint connector 
(CAN1) for open circuit.
Disconnect CAN box unit connector and joint con-
nector (CAN1), and check the following wiring har-
ness for open circuit.
(1) The wiring harness between C-54 CAN box unit 

connector terminal No.8 and C-04 joint connector 
(CAN1) terminal No.6.

OK: Continuity exists (2 

Ω or less)

(2) The wiring harness between C-54 CAN box unit 

connector terminal No.9 and C-04 joint connector 
(CAN1) terminal No.17.

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES  : 

Go to Step 39.

NO  : 

Repair the wiring harness between C-54 
CAN box unit connector and C-04 joint 
connector (CAN1).

STEP 38. Check the wiring harness between C-
103 spare connector (for audio) and C-04 joint 
connector (CAN1) for open circuit.
Disconnect joint connector (CAN1), and check the 
following wiring harness for open circuit.
(1) The wiring harness between C-103 spare 

connector (for audio) terminal No.8 and C-04 joint 
connector (CAN1) terminal No.1.

OK: Continuity exists (2 

Ω or less)

(2) The wiring harness between C-103 spare 

connector (for audio) terminal No.18 and C-04 
joint connector (CAN1) terminal No.17.

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES  : 

Go to Step 39.

NO  : 

Repair the wiring harness between C-103 
spare connector (for audio) and C-04 joint 
connector (CAN1).

STEP 39. Check the wiring harness between C-
301 ETACS-ECU connector and C-04 joint 
connector (CAN1) for open circuit.

CAUTION

Strictly observe the specified wiring harness 
repair procedure. For details refer to .
Disconnect ETACS-ECU connector and joint con-
nector (CAN1), and check the following wiring har-
ness for open circuit.
(1) The wiring harness between C-301 ETACS-ECU 

connector terminal No.6 and C-04 joint connector 
(CAN1) terminal No.11

OK: Continuity exists (2 

Ω or less)

(2) The wiring harness between C-301 ETACS-ECU 

connector terminal No.7 and C-04 joint connector 
(CAN1) terminal No.22

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES : 

Go to Step 47.

NO : 

Repair the wiring harness between C-301 
ETACS-ECU connector and C-04 joint 
connector (CAN1).

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-138

STEP 40. M.U.T.-III CAN bus diagnostics 
(checking the SRS-ECU for internal short)

CAUTION

Strictly observe the specified wiring harness 
repair procedure. For details refer to .
Disconnect C-122 SRS-ECU 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-122 

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

NO : 

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

STEP 41. M.U.T.-III CAN bus diagnostics 
(checking the heater control unit <vehicles 
without A/C> or A/C-ECU <vehicles with A/C> for 
internal short)

CAUTION

Strictly observe the specified wiring harness 
repair procedure. For details refer to .
Disconnect C-60 heater control unit connector <vehi-
cles without A/C> or C-15 A/C-ECU connector <vehi-
cles with A/C>, 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-60 

heater control unit connector <vehicles 
without A/C> or C-15 A/C-ECU connector 
<vehicles with A/C> and C-04 joint 
connector (CAN1).

NO : 

Check the heater control unit connector 
<vehicles without A/C> or A/C-ECU 
connector <vehicles with A/C>, and repair if 
necessary. If the heater control unit 
connector <vehicles without A/C> or A/C-
ECU connector <vehicles with A/C> is in 
good condition, replace the heater control 
unit <vehicles without A/C> or A/C-ECU 
<vehicles with A/C>.

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-139

STEP 42. M.U.T.-III CAN bus diagnostics 
(checking the combination meter for internal 
short)

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 43 M.U.T.-III CAN bus diagnostics 
(checking the WCM for internal short)

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 44. M.U.T.-III CAN bus diagnostics 
(checking the KOS-ECU for internal short)

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?