Mitsubishi Evolution X. Manual - part 1124

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-131

.

FUNCTION

If the scan tool MB991958 cannot communicate with 
the SRS-ECU, this diagnosis result will be set.

.

TROUBLE JUDGEMENT CONDITIONS

If a communication flag is not set for the SRS-ECU, 
the ETACS-ECU determines that there is a failure.

.

TROUBLESHOOTING HINTS

• Malfunction of the connector [joint connector 

(CAN1), SRS-ECU connector improperly con-
nected]

• Malfunction of the wiring harness [open circuit 

between the SRS-ECU connector and the joint 
connector (CAN1), power supply circuit to the 
SRS-ECU]

• Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB992006: Extra Fine Probe

STEP 1. Check joint connector (CAN1) C-105 and SRS-ECU 
connector C-37 for loose, corroded or damaged terminals, 
or terminals pushed back in the connector.

CAUTION

The strand end of the twisted wire should be within 10 cm 
(4 inches) from the connector. For details refer to 

P.54C-7

.

Q: Are joint connector (CAN1) C-105 and SRS-ECU 

connector C-37 in good condition?
YES : Go to Step 2.
NO :  Repair the damaged parts.

AC708951AC

C-37 (Y)

Connector: C-37

AC708950

Connector: C-105

BL

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-132

STEP 2. Check the wiring harness between joint connector 
(CAN1) C-105 and SRS-ECU connector C-37 for open 
circuit.

CAUTION

Strictly observe the specified wiring harness repair proce-
dure. For details refer to 

P.54C-7

.

(1) Disconnect joint connector (CAN1) C-105 and SRS-ECU 

connector C-37, and check the wiring harness.

(2) Check the wiring harness between joint connector (CAN1) 

C-105 (terminal 8) and SRS-ECU connector C-37 (terminal 
15)

OK: Continuity exists (2 

Ω or less)

(3) Check the wiring harness between joint connector (CAN1) 

C-105 (terminal 21) and SRS-ECU connector C-37 
(terminal 16)

OK: Continuity exists (2 

Ω or less)

Q: Is the wiring harness between joint connector (CAN1) 

C-105 and SRS-ECU connector C-37 in good condition?
YES : Check the power supply circuit of the SRS-ECU. 

Refer to GROUP 52B, SRS 

− Troubleshooting 

P.52B-357

.

NO :  Repair the wiring harness between joint connector 

(CAN1) C-105 and SRS-ECU connector C-37.

AC709707

AC709707 BZ

Harness side: C-105

Harness side: C-37

TEST HARNESS

TEST 
HARNESS

AC709707 CA

Harness side: C-105

Harness side: C-37

TEST HARNESS

TEST 
HARNESS

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-133

DIAGNOSTIC ITEM 18: Diagnose when the scan tool cannot receive the data sent by occupant 

classification-ECU.

CAUTION

When servicing a CAN bus line, ground yourself by touching a metal object such as an unpainted 

water pipe. If you fail to do so, a component connected to the CAN bus line may be damaged.

CAN-B Communication Circuit

ETACS-ECU

INTERFACE
CIRCUIT

INTERFACE
CIRCUIT

CAN DRIVE
CIRCUIT

HANDS FREE
MODULE

OCCUPANT 
CLASSIFICATION-
ECU

SATELLITE
RADIO 
TUNER

RADIO AND CD
PLAYER

NOTE

VEHICLES WITHOUT MITSUBISHI MULTI-COMMUNICATION SYSTEM (MMCS)
VEHICLES WITH MITSUBISHI MULTI-COMMUNICATION SYSTEM (MMCS)

CAN
TRANSCEIVER
CIRCUIT

CAN BOX UNIT

JOINT CONNECTOR
(CAN1)

FRONT SEAT
ASSEMBLY (LH)

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-134

.

FUNCTION

If the scan tool MB991958 cannot communicate with 
the occupant classification-ECU, this diagnosis result 
will be set.

.

TROUBLE JUDGEMENT CONDITIONS

If a communication flag is not set for the occupant 
classification-ECU, the ETACS-ECU determines that 
there is a failure.

.

TROUBLESHOOTING HINTS

• Malfunction of the connector [joint connector 

(CAN1), occupant classification-ECU connector 
improperly connected]

• Malfunction of the wiring harness [open circuit 

between the occupant classification-ECU con-
nector and the joint connector (CAN1), power 
supply circuit to the occupant classification-ECU]

• Malfunction of the occupant classification-ECU

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB992006: Extra Fine Probe

STEP 1. Check joint connector (CAN1) C-105, occupant 
classification-ECU connector D-39, D-39-2 and 
intermediate connector C-41 for loose, corroded or 
damaged terminals, or terminals pushed back in the 
connector.

CAUTION

The strand end of the twisted wire should be within 10 cm 
(4 inches) from the connector. For details refer to 

P.54C-7

.

Q: Are joint connector (CAN1) C-105, occupant 

classification-ECU connector D-39, D-39-2 and 
intermediate connector C-41 in good condition?
YES : Go to Step 2.
NO :  Repair the damaged parts.

AC708950CA

C-41

C-105

Connectors: C-41, C-105

AC708954 AV

Connectors: D-39, D-39-2

D-39, 
D-39-2