Mitsubishi Lancer (4A9 engine). Manual - part 262

AC709894

AE

Connector: C-114 <LHD>

AC701121BR

Connector: C-114 <RHD>

ACB02645

AH

Connector: C-124 <LHD>

C-124 (GR)

ACB02647

AE

C-124 (GR)

Connector: C-124 <RHD>

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-72

FUNCTION
If the M.U.T.-III cannot communicate with the electric 
power steering-ECU, this diagnosis result will be set.

TROUBLE JUDGEMENT CONDITIONS
If a communication flag is not set for the electric 
power steering-ECU, the ETACS-ECU determines 
that there is a failure.

TROUBLESHOOTING HINTS

• Malfunction of the connector [joint connector 

(CAN3) or electric power steering-ECU connector 
improperly connected]

• Malfunction of the wiring harness [open circuit 

between the electric power steering-ECU and the 
joint connector (CAN3), power supply circuit to 
the electric power steering-ECU]

• Malfunction of the electric power steering-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-114 electric power 
steering-ECU connector and C-124 joint 
connector (CAN3)

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-114 
electric power steering-ECU connector and C-
124 joint connector (CAN3)

CAUTION

Strictly observe the specified wiring harness 
repair procedure. For details refer to .
Disconnect electric power steering-ECU connector 
and joint connector (CAN3), and check the following 
wiring harness for open circuit.
(1) The wiring harness between C-114 electric power 

steering-ECU connector terminal No.4 and C-124 
joint connector (CAN3) terminal No.6 <Petrol> or 
7 <Diesel> <CAN_H>

OK: Continuity exists (2 

Ω or less)

(2) The wiring harness between C-114 electric power 

steering-ECU connector terminal No.3 and C-124 
joint connector (CAN3) terminal No.17 <Petrol> 
or 18 <Diesel> <CAN_L>

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES : 

Check the power supply circuit of the 

electric power steering-ECU. Refer to 
GROUP 37B 

− Electric power steering − 

Troubleshooting .

NO : 

Repair the wiring harness.

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-73

Diagnosis Item 11: Diagnose when the M.U.T.-III cannot receive the data sent by A/T-ECU <A/T> or 
CVT-ECU <CVT>

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-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-74

ACB02645

AI

C-35

Connectors: C-32, C-35, C-124 <LHD>

C-32 (GR)

C-124 (GR)

ACB02648

AE

Connector: C-35 <RHD>

ACB02647

AE

C-124 (GR)

Connector: C-124 <RHD>

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-75

FUNCTION
If the M.U.T.-III cannot communicate with the A/T-
ECU <A/T> or CVT-ECU <CVT>, this diagnosis 
result will be set.

TROUBLE JUDGEMENT CONDITIONS
If a communication flag is not set for the A/T-ECU 
<A/T> or CVT-ECU <CVT>, the ETACS-ECU deter-
mines that there is a failure.

TROUBLESHOOTING HINTS

• Malfunction of the connector [joint connector 

(CAN3) or A/T-ECU <A/T> or CVT-ECU <CVT> 
improperly connected]

• Malfunction of the wiring harness [open circuit 

between the A/T-ECU <A/T> or CVT-ECU <CVT> 
and the joint connector (CAN3), power supply cir-
cuit to the A/T-ECU <A/T> or CVT-ECU <CVT>]

• Malfunction of the A/T-ECU <A/T> or CVT-ECU 

<CVT>

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-124 joint connector 
(CAN3) and C-32 A/T-ECU connector <A/T> or C-
35 CVT-ECU connector <CVT>

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-32 
A/T-ECU connector <A/T> or C-35 CVT-ECU 
connector <CVT> and C-124 joint connector 
(CAN3)

CAUTION

Strictly observe the specified wiring harness 
repair procedure. For details refer to .
Disconnect shift lever connector and joint connector 
(CAN3), and check the following wiring harness for 
open circuit.
(1) The wiring harness between C-32 A/T-ECU <A/

T> or C-35 CVT-ECU <CVT> connector terminal 
No.4 and C-124 joint connector (CAN3) terminal 
No.8 <CAN_H>

OK: Continuity exists (2 

Ω or less)

(2) The wiring harness between C-32 A/T-ECU <A/

T> or C-35 CVT-ECU <CVT> connector terminal 
No.5 and C-124 joint connector (CAN3) terminal 
No.19 <CAN_L>

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES : 

Check the power supply circuit of the CVT-

ECU <CVT> or A/T-ECU <A/T>. Refer to 
GROUP 23A 

− Troubleshooting  <CVT> or 

GROUP 23C 

− Troubleshooting  <A/T>.

NO : 

Repair the wiring harness.