Mitsubishi Lancer (4A9 engine). Manual - part 264

CAN-C Communication Circuit <Except for RALLIART>

ETACS-ECU

INTERFACE 
CIRCUIT

CAN DRIVE 
CIRCUIT

ASC-ECU

A/T-ECU

ABS-ECU

CVT-ECU

STEERING 
WHEEL SENSOR 
<AFS, ASC>

ENGINE-ECU

ELECTRIC 
POWER 
STEERING-ECU

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

CORNER SENSOR/
BACK SENSOR-ECU

DIESEL

:

PETROL

:

1800-PETROL, 2000

:

NOTE

PETROL (EXCEPT SOHC)

:

VEHICLES WITHOUT ASC

:

VEHICLES WITH ASC

:

HEADLAMP 
AUTOMATIC 
LEVELLING-ECU

AS&G-ECU

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-80

AC709893

AM

Connector: C-03 <LHD>

AC701121BP

Connector: C-03 <RHD>

ACA00886

BE

Connector: C-301 <LHD>
ETACS-ECU

ACA00887

BF

Connector: C-301 <RHD>
ETACS-ECU

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-81

FUNCTION
If a failure is present in the wiring harness between 
the ETACS-ECU connector and the joint connector 
(CAN2), this diagnosis result will be set.

TROUBLE JUDGEMENT CONDITIONS
If a communication flag is not set for any ECU con-
nected to CAN-C (CAN2 and CAN3), it is determined 
that a failure has occurred.

TROUBLESHOOTING HINTS

• Malfunction of the connector [joint connector 

(CAN2) or ETACS-ECU connector improperly 
connected]

• Malfunction of the wiring harness [open circuit 

between the ETACS-ECU connector and the joint 
connector (CAN2), power supply circuit to the 
engine-ECU]

• Malfunction of the ETACS-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-03 joint connector 
(CAN2) and C-301 ETACS-ECU connector

CAUTION

The strand end of the twist wire should be within 
10 cm from the connector. For details refer to .

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Repair the defective connector.

STEP 2. Check the wiring harness between C-301 
ETACS-ECU connector and C-03 joint connector 
(CAN2)

CAUTION

Strictly observe the specified wiring harness 
repair procedure. For details refer to .
Disconnect ETACS-ECU connector and joint con-
nector (CAN2), 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-03 joint connector 
(CAN2) terminal No.11 <CAN_H>

OK: Continuity exists (2 

Ω or less)

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

connector terminal No.7 and C-03 joint connector 
(CAN2) terminal No.22 <CAN_L>

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the wiring harness.

STEP 3. Trouble symptom check
Diagnose the CAN bus line, and check that normal 
condition is displayed.

Q: Is the check result normal?

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-82

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 : 

Replace the ETACS-ECU.

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-83

Diagnosis Item 14: Diagnose the lines between joint connector (CAN2) and joint connector (CAN3)

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.