Mitsubishi Evolution X. Manual - part 532

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-35

STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set to the KOS-ECU.
(1) Turn the ignition switch from "LOCK" (OFF) position to "ON" 

position.

(2) Check if DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Go to Step 5.
NO :  The trouble can be an intermittent malfunction (Refer 

to GROUP 00 

− How to use 

Troubleshooting/inspection Service Points 

− How to 

Cope with Intermittent Malfunction 

P.00-15

).

STEP 5. Replace the keyless operation key and recheck 
the diagnostic trouble code.
Replace the keyless operation key for which the DTC is set 
with the other key,  and check whether the DTC is reset.
(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 :  Go to Step 7.

STEP 6. Register the key ID and recheck the diagnostic 
trouble code.
Register the key ID and keyless operation key ID of the keyless 
operation key by which the DTC is set (refer to 

P.42B-12

), 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 7.
NO :  The procedure is complete.

STEP 7. Replace the keyless operation key and recheck 
the diagnostic trouble code.
Replace the keyless operation key for which the DTC is set 
with a new one, register the key ID and keyless operation key 
ID (refer to 

P.42B-12

), and check whether the DTC is reset.

(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 KOS-ECU and register the ID codes (Refer 

to 

P.42B-12

).

NO :  The procedure is complete.

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-36

DTC B2101: IG SW start POS.circuit low

 

DTC B2102: IG SW start POS.circuit high

CAUTION

• If DTC B2101 or B2102 is set in KOS-ECU, 

always diagnose the CAN bus lines.

• Before replacing the ECU, ensure that the 

communication circuit is normal.

.

KOS-ECU Communication Circuit

34

FUSIBLE
LINK

IGNITION
SWITCH (IG1)

ETACS-
ECU

IG1
RELAY

KOS-ECU

POWER
SUPPLY

AC708950AZ

Connector: C-05

AC708972AB

Connector: C-317

Junction block

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-37

DTC SET CONDITION

If the actual ignition switch status is different from the 
ignition switch status information received from 
ETACS-ECU via CAN, KOS-ECU sets diagnostic 
trouble code No. B2101 or B2102.

.

TECHNICAL DESCRIPTION (COMMENT)

If the difference in the ignition switch level shown 
below occurs consecutively 10 times with the ignition 
switch in the ON position or START position, when 
the CAN message (ignition switch position informa-
tion) from ETACS-ECU, KOS-ECU determines that 
there is a problem.

B2101

• Status of ignition switch: ON position

• Ignition switch position information: OFF

B2102

• Status of ignition switch: OFF position

• Ignition switch position information: ON

.

TROUBLESHOOTING HINTS

• Malfunction of CAN bus line

• Malfunction of the KOS-ECU

• 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: Vehicles 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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KEYLESS OPERATION SYSTEM (KOS)

42B-38

STEP 2. Check ETACS-ECU connector C-317 and 
KOS-ECU connector C-05 for loose, corroded or damaged 
terminals, or terminals pushed back in the connector.
Q: Is ETACS-ECU connector C-317 and KOS-ECU 

connector C-05 in good condition?
YES : Go to Step 3.
NO :  Repair the defective connector.

STEP 3. Check the wiring harness between KOS-ECU 
connector C-05 (terminal No.39) and ETACS-ECU 
connector C-317 (terminal No.5) for open circuit.
(1) Disconnect KOS-ECU connector C-05 and ETACS-ECU 

connector C-317, and check the wiring harness.

(2) Check the wiring harness between KOS-ECU connector 

C-05 (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 KOS-ECU connector C-05 

(terminal No. 39) and ETACS-ECU connector C-317 
(terminal No. 5) in good condition?
YES : Go to Step 4.
NO :  Repair the wiring harness between KOS-ECU 

connector C-05 (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

).

AC709707EO

Harness side: C-05

Harness side: C-317

Item No.

Item name

Normal 
conditions

Item 254

IG voltage

Battery 
voltage