Mitsubishi Evolution X. Manual - part 539

DIAGNOSIS

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-63

DTC SET CONDITION

When the ignition push switch is pressed, the steer-
ing lock unit communicates with KOS-ECU to unlock 
the IG knob. However, if there is a failure shown 
below, the corresponding DTC is set.

• B2402: System ID (vehicle specific code) failure

• B2403: Cyclic Redundancy Check (CRC): The 

error detection strategy to detect a continuously 
occurring error (burst error), the calculation result 
discrepancy

• B2404: Function code failure

• B2405: Rolling code (automatically changing a 

code for lock/unlock each time when a lock oper-
ation is performed)

• B2406: PTC thermistor continuously activated or 

activated to prevent solenoid abnormal heating 
on the communication with steering lock unit

• B2407: EEPROM failure

• B2408: Communication error between the steer-

ing lock unit and KOS-ECU, or solenoid failure

.

TECHNICAL DESCRIPTION (COMMENT)

Range of check

• When the IG knob unlock communication is per-

formed by pressing the ignition push switch

Judgment criteria

• B2402: Steering lock unit communication error 

(system ID) or received system ID error

• B2403: Steering lock unit communication error 

(CRC) or received frame CRC calculation result 
discrepancy

• B2404: Steering lock unit communication error 

(function code) or received frame function code 
undefined

• B2405: Steering lock unit communication error 

(rolling code) or received rolling code out of the 
permissible range

• B2406: Steering lock unit communication error 

(PTC operation) or PTC thermistor activated to 
prevent solenoid abnormal heating

• B2407: Steering lock unit communication error 

(EEPROM) or RRPROM failure

• B2408: Steering lock unit communication error 

(solenoid) or solenoid failure

.

TROUBLESHOOTING HINTS

• Malfunction of the key reminder switch (inte-

grated into the steering lock unit)

• Wiring harness or connector failure of CAN bus 

line

• Malfunction of the KOS-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

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-64

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

).

STEP 2. Check key reminder switch connector C-211 and 
KOS-ECU connector C-05 for loose, corroded or damaged 
terminals, or terminals pushed back in the connector.
Q: Is the key reminder switch connector C-211 and 

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

ZC501967

AC404789

AC701411AB

MB991824

MB991827

MB991910

Data link 
connector

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-65

STEP 3. Wiring harness check between C-211 key reminder 
switch connector and C-05 KOS-ECU connector for open 
circuit.
(1) Disconnect C-211 key reminder switch connector and C-05 

KOS-ECU connector.

(2) Measure at the connector side of C-211 key reminder 

switch connector and C-05 KOS-ECU connector.

(3) Measure the resistance between the terminals.

•

C-211 key reminder switch connector terminal No.9 

− 

C-05 KOS-ECU connector terminal No.5.

•

C-211 key reminder switch connector terminal No.12 

− 

C-05 KOS-ECU connector terminal No.4.

OK: Continuity exists (2

Ω or less)

Q: Is the check result normal?

YES : Go to Step 4.
NO (C-211 key reminder switch connector terminal No.9 
− C-05 KOS-ECU connector terminal No.5.) : An open 

circuit is present in the wiring harness between C-211 
key reminder switch connector terminal No. 9 and 
C-05 KOS-ECU connector terminal No. 5. Repair the 
wiring harness.

NO (C-211 key reminder switch connector terminal 
No.12 

− C-05 KOS-ECU connector terminal No.4.) : An 

open circuit is present in the wiring harness between 
C-211 key reminder switch connector terminal No. 12 
and C-05 KOS-ECU connector terminal No. 4. Repair 
the wiring harness.

AC709710 AB

Harness side: C-05

Harness side: C-211

AC709710 AD

Harness side: C-05

Harness side: C-211

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-66

STEP 4. Check the wiring harness between the C-211 key 
reminder switch connector (terminal Nos. 9, 12) and the 
ground for short circuit.
(1) Disconnect C-211 key reminder switch connector, and 

check the wiring harness.

(2) Check the wiring harness between C-211 key reminder 

switch connector (terminal No.9) and ground

OK: No Continuity

(3) Check the wiring harness between C-211 key reminder 

switch connector (terminal No.12) and ground

OK: No Continuity

Q: Is the wiring harness between C-211 key reminder 

switch connector (terminal No. 9, 12) and the ground in 
good condition?
YES  : Go to Step 5.
NO (key reminder switch connector C-211 terminal No.9 
− ground.) : Repair the wiring harness between C-211 key 

reminder switch connector (terminal No. 9) and the 
ground.

NO (key reminder switch connector C-211 terminal 
No.12 

− ground.) : Repair the wiring harness C-211 key 

reminder switch connector (terminal No. 12) and the 
ground.

STEP 5. Replace the key reminder switch, and check 
whether the diagnostic trouble code is reset.
(1) Erase the DTC.
(2) Turn the ignition switch from the "LOCK" (OFF) position to 

the "ON" position.

(3) 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 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

).

AC709703AG

Harness side: C-211

AC709703AI

Harness side: C-211