Mitsubishi Evolution X. Manual - part 603

DIAGNOSIS

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WIRELESS CONTROL MODULE (WCM)

42C-29

STEP 4. Replace the ignition key and recheck the 
diagnostic trouble code.
Replace the ignition key by which the DTC is set with  the other 
key, and recheck if the DTC is set.
(1) Turn the ignition switch from the "LOCK" (OFF) position to 

the "ON" position.

(2) Check if the DTC is set.
Q: Is the DTC set?

YES : Go to Step 5.
NO :  Go to Step 6.

STEP 5. Register the key ID and recheck the diagnostic 
trouble code.
Register the key ID of the ignition key (refer to 

P.42C-9

), and 

recheck if the DTC is set.
(1) Turn the ignition switch from the "LOCK" (OFF) position to 

the "ON" position.

(2) Check if the DTC is set.
Q: Is the DTC set?

YES : Go to Step 6.
NO :  The procedure is complete.

STEP 6. Replace the ignition key and recheck the 
diagnostic trouble code.
Replace the ignition key by which the DTC is set with a new 
one, register the key ID of the new key, (refer to 

P.42C-9

), and 

recheck if the DTC is set.
(1) Turn the ignition switch from the "LOCK" (OFF) position to 

the "ON" position.

(2) Check if the DTC is set.
Q: Is the DTC set?

YES : Replace WCM and register the ID codes (Refer to 

P.42C-9

).

NO :  The procedure is complete.

DIAGNOSIS

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WIRELESS CONTROL MODULE (WCM)

42C-30

DTC B2101: IG SW start POS.circuit low

 

DTC B2102: IG SW start POS.circuit high

CAUTION

• If DTC B2101 or B2102 is set, be sure to diag-

nose the CAN bus line.

• Before replacing the ECU, ensure that the 

communication circuit is normal.

.

WCM Communication Circuit

34

FUSIBLE
LINK

IGNITION
SWITCH (IG1)

ETACS-
ECU

IMMOBILIZER
ANTENNA

KEY ID

TRANSPONDER

IG1
RELAY

WCM

AC708951CD

Connector: C-07

C-07

AC708972AB

Connector: C-317

Junction block

DIAGNOSIS

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WIRELESS CONTROL MODULE (WCM)

42C-31

DTC SET CONDITION

WCM sets DTC B2101 or B2102 when the actual 
state of the ignition switch and the ignition switch 
position information received from ETACS-ECU via 
CAN do not match.

.

TECHNICAL DESCRIPTION (COMMENT)

WCM determines that the abnormality is present, if it 
has detected discrepancy in the ignition switch level 
shown below ten consecutive times when WCM has 
received the CAN message (ignition switch position 
information) from ETACS-ECU with the ignition 
switch turned to the ON or START position.

B2101

• Status of ignition switch: OFF position

• Ignition switch position information from the 

ETACS-ECU: ON

B2102

• Status of ignition switch: ON position

• Ignition switch position information from the 

ETACS-ECU: OFF

.

TROUBLESHOOTING HINTS

• Malfunction of CAN bus line

• Malfunction of the WCM

• Malfunction of the ignition switch

• Damaged wiring harness and connectors

• Malfunction of ETACS-ECU

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, diagnose the CAN bus 
line.

CAUTION

To prevent damage to scan tool (MB991958), always turn 
the ignition switch to the "LOCK" (OFF) position before 
connecting or disconnecting scan tool (MB991958).
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.
NO :  Repair the CAN bus line (Refer to GROUP 54C, 

Diagnosis 

P.54C-14

).

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

DIAGNOSIS

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WIRELESS CONTROL MODULE (WCM)

42C-32

STEP 2. Check ETACS-ECU connector C-317 and WCM 
connector C-07 for loose, corroded or damaged terminals, 
or terminals pushed back in the connector.
Q: Is ETACS-ECU connector C-317 and WCM connector 

C-07 in good condition?
YES : Go to Step 3.
NO :  Repair the defective connector.

STEP 3. Check the wiring harness between WCM 
connector C-07 (terminal No.9) and the ETACS-ECU 
connector C-317 (terminal No.5) for open circuit.
(1) Disconnect WCM connector C-07 and ETACS-ECU 

connector C-317, and check the wiring harness.

(2) Check the wiring harness between WCM connector C-07 

(terminal No.9) and ETACS-ECU connector C-317 (terminal 
No.5)

OK: Continuity exists (2 

Ω or less)

Q: Is the wiring harness between WCM connector C-07 

(terminal No.9) and the ETACS-ECU connector C-317 
(terminal No.5) in good condition?
YES : Go to Step 4.
NO :  Repair the wiring harness between WCM connector 

C-07 (terminal No.9) and ETACS-ECU connector 
C-317 (terminal No.5).

STEP 4. Using scan tool MB991958, check data list.
Use the ETACS-ECU data list to check the signals related to 
the ignition voltage.
(1) Turn the ignition switch from "LOCK" (OFF) position to "ON" 

position.

Q: Does scan tool MB991958 display the item "IG voltage" 

as normal condition?
YES : Go to Step 5.
NO :  Diagnose the ETACS-ECU (Refer to GROUP 54A 

− 

ETACS, Diagnosis 

P.54A-582

).

AC709707

AC709707EP

Harness side: C-07

Harness side: C-317

Item No.

Item name

Normal 
condition

Item 254

IG voltage

Battery 
voltage