Mitsubishi Evolution X. Manual - part 1125

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-135

STEP 2. Check the wiring harness between joint connector 
(CAN1) C-105 and occupant classification-ECU connector 
D-39-2 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 occupant 

classification-ECU connector D-39-2, and check the wiring 
harness.

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

C-105 (terminal 11) and occupant classification-ECU 
connector D-39-2 (terminal 24)

OK: Continuity exists (2 

Ω or less)

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

C-105 (terminal 24) and occupant classification-ECU 
connector D-39-2 (terminal 25)

OK: Continuity exists (2 

Ω or less)

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

C-105 and occupant classification-ECU connector 
D-39-2 in good condition?
YES : Check the power supply circuit of the occupant 

classification-ECU. Refer to GROUP 52B, SRS air 
bag Diagnosis 

P.52B-357

.

NO :  Repair the wiring harness between joint connector 

(CAN1) C-105 and occupant classification-ECU 
connector D-39-2.

AC709707

AC709707 CB

Harness side: C-105

Harness side: D-39-2

TEST HARNESS

TEST HARNESS

AC709707 CC

Harness side: C-105

Harness side: D-39-2

TEST HARNESS

TEST 
HARNESS

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-136

DIAGNOSTIC ITEM 19: Diagnose when the scan tool cannot receive the data sent by A/C-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

CAN DRIVE
CIRCUIT

A/C-ECU

COMBINATION
METER

SRS-ECU

WIRELESS
CONTROL
MODULE

KOS-ECU

NOTE

VEHICLES WITH WCM
VEHICLES WITH KOS

CAN DRIVE
CIRCUIT

CAN DRIVE
CIRCUIT

CAN DRIVE
CIRCUIT

JOINT CONNECTOR
(CAN1)

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-137

.

FUNCTION

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

.

TROUBLE JUDGEMENT CONDITIONS

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

.

TROUBLESHOOTING HINTS

• Malfunction of the connector [joint connector 

(CAN1), A/C-ECU connector improperly con-
nected]

• Malfunction of the wiring harness [open circuit 

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

• Malfunction of the A/C-ECU

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB992006: Extra Fine Probe

STEP 1. Check joint connector (CAN1) C-105 and A/C-ECU 
connector C-22 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 A/C-ECU 

connector C-22 in good condition?
YES : Go to Step 2.
NO :  Repair the damaged parts.

AC708951CE

Connector: C-22

C-22 (B)

AC708950

Connector: C-105

BL

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-138

STEP 2. Check the wiring harness between joint connector 
(CAN1) C-105 and A/C-ECU connector C-22 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 A/C-ECU 

connector C-22, and check the wiring harness.

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

C-105 (terminal 1) and A/C-ECU connector C-22 (terminal 
11)

OK: Continuity exists (2 

Ω or less)

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

C-105 (terminal 12) and A/C-ECU connector C-22 (terminal 
12)

OK: Continuity exists (2 

Ω or less)

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

C-105 and A/C-ECU connector C-22 in good condition?
YES : Check the power supply circuit of the A/C-ECU. Refer 

to GROUP 55, Diagnosis 

P.55-71

.

NO :  Repair the wiring harness between joint connector 

(CAN1) C-105 and A/C-ECU connector C-22.

AC709707

AC709707 CD

Harness side: C-105

Harness side: C-22

TEST HARNESS

TEST 
HARNESS

AC709707 CE

Harness side: C-105

Harness side: C-22

TEST 
HARNESS

TEST 
HARNESS