Mitsubishi Lancer (4A9 engine). Manual — part 271

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-108

Diagnosis Item 22: Diagnose when the M.U.T.-III cannot receive the data sent by AS&G-ECU <vehicles
with automatic stop & go (AS&G) system>

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-109

ACA00830AD

Connector: C-64 <LHD>

C-64

ACB02647

AO

C-64

C-124 (GR)

Connectors: C-64, C-124 <RHD>

ACB02645

AH

Connector: C-124 <LHD>

C-124 (GR)

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-110

FUNCTION
If the M.U.T.-III cannot communicate with the AS&G-
ECU, this diagnosis result will be set.

TROUBLE JUDGMENT CONDITIONS
If a communication flag is not set for the AS&G-ECU,
the ETACS-ECU determines that there is a failure.

TROUBLESHOOTING HINTS

• Malfunction of the connector [joint connector

(CAN3) or AS&G-ECU connector improperly con-
nected]

• Malfunction of the wiring harness [open circuit

between the AS&G-ECU and the joint connector
(CAN3), power supply circuit to the AS&G-ECU]

• Malfunction of the AS&G-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-04 joint connector
(CAN1) and C-64 AS&G-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-64
AS&G-ECU connector and C-124 joint connector
(CAN1)

CAUTION

Strictly observe the specified wiring harness
repair procedure. For details refer to .
Disconnect hands AS&G-ECU connector and joint
connector (CAN1), and check the continuity of the
following wiring harness.
(1) The wiring harness between C-64 AS&G-ECU

connector terminal No.1 and C-124 joint
connector (CAN3) terminal No.17 <Diesel> or 16
<Petrol> <CAN_H>

OK: Continuity exists (2

Ω or less)

(2) The wiring harness between C-64 AS&G-ECU

connector terminal No.14 and C-124 joint
connector (CAN3) terminal No.6 <Diesel> or 5
<Petrol> <CAN_L>

OK: Continuity exists (2

Ω or less)

Q: Is the check result normal?

YES :

Check the power supply circuit of the hands

free-ECU. Refer to GROUP 17

− automatic

stop & go (AS&G) system

− Troubleshooting

.

NO :

Repair the wiring harness.

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-111

Diagnosis Item 23: Short to power supply or earth in both CAN_H and CAN_L lines of the CAN-B bus
lines.

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.