Mitsubishi Lancer (4A9 engine). Manual - part 257

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-52

STEP 7. Check the wiring harness between C-114 
electric power steering-ECU connector and C-
124 joint connector (CAN3) for short to power 
supply (voltage measurement).

CAUTION

• A digital multimeter should be used. For 

details refer to .

• The test wiring harness should be used. For 

details refer to .

(1) Disconnect joint connector (CAN3), and measure 

at the wiring harness side.

(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between C-124 joint 

connector (CAN3) terminal No.6 <Petrol> or 7 
<Diesel> and body earth.

OK: 4.7 V or less

(4) Measure the voltage between C-124 joint 

connector (CAN3) terminal No.17 <Petrol> or 18 
<Diesel> and body earth.

OK: 4.7 V or less

Q: Is the check result normal?

YES <vehicles with automatic stop & go (AS&G) 
system> : 

Go to Step 8.

YES <vehicles without automatic stop & go (AS&G) 
system> : 

Go to Step 9.

NO  : 

Go to Step 16.

STEP 8. Check the wiring harness between C-64 
AS&G-ECU connector and C-124 joint connector 
(CAN3) for short to power supply (voltage 
measurement).

CAUTION

• A digital multimeter should be used. For 

details refer to .

• The test wiring harness should be used. For 

details refer to .

(1) Disconnect joint connector (CAN3), and measure 

at the wiring harness side.

(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between C-124 joint 

connector (CAN3) terminal No.16 <Petrol> or 17 
<Diesel> and body earth

OK: 4.7 V or less

(4) Measure the voltage between C-124 joint 

connector (CAN3) terminal No.5 <Petrol> or 6 
<Diesel> and body earth

OK: 4.7 V or less

Q: Is the check result normal?

YES : 

Go to Step 9.

NO : 

Go to Step 17.

STEP 9. Check the wiring harness between B-09 
<Petrol> or B-40 <Diesel> engine-ECU connector 
and C-124 joint connector (CAN3) for short to 
power supply (voltage measurement).

CAUTION

• A digital multimeter should be used. For 

details refer to .

• The test wiring harness should be used. For 

details refer to .

(1) Disconnect joint connector (CAN3), and measure 

at the wiring harness side.

(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between C-124 joint 

connector (CAN3) terminal No.10 and body 
earth.

OK: 4.7 V or less

(4) Measure the voltage between C-124 joint 

connector (CAN3) terminal No.21 and body 
earth.

OK: 4.7 V or less

Q: Is the check result normal?

YES : 

Check C-127 intermediate connector, and 

repair if necessary. If the intermediate 
connector is in good condition, repair the 
wiring harness between C-03 joint 
connector (CAN2) and C-124 joint 
connector (CAN3).

NO : 

Go to Step 18.

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-53

STEP 10. M.U.T.-III CAN bus diagnostics 
(checking the steering wheel sensor for internal 
short to earth)

CAUTION

Strictly observe the specified wiring harness 
repair procedure. For details refer to .
Disconnect C-211 steering wheel sensor connector, 
and diagnose the CAN bus line.

ACB01921AB

M.U.T.

JC

JC

SAS

KOS/
WCM

SRS

A/C

AUDIO

METER

AT/

CVT

EPS

ENGINE

ETACS

ABS/

ASC

MMCS

: Red section on screen

AS&G

Levelling

Cor ner

JC

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-211 

steering wheel sensor connector and C-03 
joint connector (CAN2).

NO : 

Check the steering wheel sensor connector, 
and repair if necessary. If the steering wheel 
sensor connector is in good condition, 
replace the steering wheel sensor.

STEP 11. M.U.T.-III CAN bus diagnostics 
(checking the corner sensor/back sensor-ECU 
for internal short to earth)

CAUTION

Strictly observe the specified wiring harness 
repair procedure. For details refer to .
Disconnect C-40 corner sensor/back sensor-ECU 
connector, and diagnose the CAN bus line.

ACB01921AB

M.U.T.

JC

JC

SAS

KOS/
WCM

SRS

A/C

AUDIO

METER

AT/

CVT

EPS

ENGINE

ETACS

ABS/

ASC

MMCS

: Red section on screen

AS&G

Levelling

Cor ner

JC

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-40 

corner sensor/back sensor-ECU connector 
and C-03 joint connector (CAN2).

NO : 

Check the corner sensor/back sensor-ECU 
connector, and repair if necessary. If the 
corner sensor/back sensor-ECU connector 
is in good condition, replace the corner 
sensor/back sensor-ECU.

STEP 12. Check the wiring harness between C-
301 ETACS-ECU connector and C-03 joint 
connector (CAN2) for short to power supply 
(voltage measurement).

CAUTION

• Disconnect the negative battery terminal. For 

details refer to .

• A digital multimeter should be used. For 

details refer to .

• The test wiring harness should be used. For 

details refer to .

• Strictly observe the specified wiring harness 

repair procedure. For details refer to .

(1) Disconnect ETACS-ECU connector and joint 

connector (CAN2), and measure at the wiring 
harness side.

(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between C-03 joint 

connector (CAN2) terminal No.11 and body earth. 

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-54

<CAN_H>

OK: 1 V or less

(4) Measure the voltage between C-03 joint 

connector (CAN2) terminal No.22 and body 
earth. <CAN_L>

OK: 1 V or less

Q: Is the check result normal?

YES : 

Check the ETACS-ECU connector, and 

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

NO : 

Repair the wiring harness between C-301 
ETACS-ECU connector and C-03 joint 
connector (CAN2).

STEP 13. M.U.T.-III CAN bus diagnostics 
(checking the headlamp automatic levelling-ECU 
for internal short to earth)

CAUTION

Strictly observe the specified wiring harness 
repair procedure. For details refer to .
Disconnect C-14 headlamp automatic levelling-ECU 
connector, and diagnose the CAN bus line.

ACB01921AB

M.U.T.

JC

JC

SAS

KOS/
WCM

SRS

A/C

AUDIO

METER

AT/

CVT

EPS

ENGINE

ETACS

ABS/

ASC

MMCS

: Red section on screen

AS&G

Levelling

Cor ner

JC

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-14 

headlamp automatic levelling-ECU 
connector and C-124 joint connector 
(CAN3).

NO : 

Check the C-14 headlamp automatic 
levelling-ECU connector, and repair if 
necessary. If the C-14 headlamp automatic 
levelling-ECU connector is in good 
condition, replace the C-14 headlamp 
automatic levelling-ECU.

STEP 14. M.U.T.-III CAN bus diagnostics 
(checking the ABS-ECU <vehicles without ASC> 
or ASC-ECU <vehicles with ASC> for internal 
short to earth)

CAUTION

Strictly observe the specified wiring harness 
repair procedure. For details refer to .
Disconnect A-04 ABS-ECU connector <vehicles 
without ASC> or A-58 ASC-ECU connector <vehi-
cles with ASC>, and diagnose the CAN bus line.

ACB01921AB

M.U.T.

JC

JC

SAS

KOS/
WCM

SRS

A/C

AUDIO

METER

AT/

CVT

EPS

ENGINE

ETACS

ABS/

ASC

MMCS

: Red section on screen

AS&G

Levelling

Cor ner

JC

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 A-04 

ABS-ECU connector <vehicles without 
ASC> or A-58 ASC-ECU connector 
<vehicles with ASC> and C-124 joint 
connector (CAN3).

NO : 

Check the ABS-ECU connector <vehicles 
without ASC> or ASC-ECU connector 
<vehicles with ASC>, and repair if 
necessary. If the ABS-ECU connector 
<vehicles without ASC> or ASC-ECU 
connector <vehicles with ASC> is in good 
condition, replace the ABS-ECU <vehicles 
without ASC> or ASC-ECU <vehicles with 
ASC>.

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-55

STEP 15. M.U.T.-III CAN bus diagnostics 
(checking the A/T-ECU <A/T> or CVT-ECU <CVT> 
for internal short to earth)

CAUTION

Strictly observe the specified wiring harness 
repair procedure. For details refer to .
Disconnect C-32 A/T-ECU connector <A/T> or C-35 
CVT-ECU connector <CVT>, and diagnose the CAN 
bus line.

ACB01921AB

M.U.T.

JC

JC

SAS

KOS/
WCM

SRS

A/C

AUDIO

METER

AT/

CVT

EPS

ENGINE

ETACS

ABS/

ASC

MMCS

: Red section on screen

AS&G

Levelling

Cor ner

JC

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-32 A/

T-ECU connector <A/T> or C-35 CVT-ECU 
connector <CVT> and C-124 joint connector 
(CAN3).

NO : 

Check the A/T-ECU connector <A/T> or 
CVT-ECU connector <CVT>, and repair if 
necessary. If the A/T-ECU connector <A/T> 
or CVT-ECU connector <CVT> is in good 
condition, replace the A/T-ECU <A/T> or 
CVT-ECU <CVT>.

STEP 16. M.U.T.-III CAN bus diagnostics 
(checking the electric power steering-ECU> for 
internal short to earth)

CAUTION

Strictly observe the specified wiring harness 
repair procedure. For details refer to .
Disconnect C-114 electric power steering-ECU con-
nector, and diagnose the CAN bus line.

ACB01921AB

M.U.T.

JC

JC

SAS

KOS/
WCM

SRS

A/C

AUDIO

METER

AT/

CVT

EPS

ENGINE

ETACS

ABS/

ASC

MMCS

: Red section on screen

AS&G

Levelling

Cor ner

JC

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-114 

electric power steering-ECU connector and 
C-124 joint connector (CAN3).

NO : 

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