Mitsubishi Evolution X. Manual - part 570

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-187

STEP 3. Check the wiring harness between the KOS-ECU 
connector C-05 (terminal No.38, 39) and the ground for 
short circuit.
(1) Disconnect KOS-ECU connector C-05, and check the 

wiring harness.

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

C-05 (terminal No.38) and ground

OK: No continuity

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

C-05 (terminal No.39) and ground

OK: No continuity

Q: Is the wiring harness between KOS-ECU connector C-05 

(terminal No.38, 39) and the ground in good condition?
YES : Go to Step 4.
NO :  Repair the wiring harness between KOS-ECU 

connector C-05 (terminal No.38, 39) and the ground.

STEP 4. Check the wiring harness between the KOS-ECU 
connector C-05 and the ground for open circuit.
(1) Disconnect KOS-ECU connector C-05, and check the 

wiring harness.

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

C-05 (terminal No.14) and ground.

OK: Continuity exists (2 

Ω or less)

Q: Is the wiring harness between KOS-ECU connector C-05 

and the ground in good condition?
YES : Go to Step 5.
NO :  Repair the wiring harness between KOS-ECU 

connector C-07 and ground.

STEP 5. Retest the system
Q: Does the abnormality in KOS-ECU power supply and 

ground circuits in good condition?
YES : 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

).

NO :  Replace KOS-ECU and register the ID codes (Refer 

to 

P.42B-12

).

AC709707HO

Harness side: C-05

AC709707HN

Harness side: C-05

AC709707

AC709707EM

Harness side: C-05

DIAGNOSIS

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KEYLESS OPERATION SYSTEM (KOS)

42B-188

Inspection Procedure 4: Keyless operation warning display does not disappear.

CAUTION

Before replacing the ECU, ensure that the power 
supply circuit, the ground circuit and the com-
munication circuit are normal.

.

TROUBLESHOOTING HINTS

• Malfunction of CAN bus line

• Malfunction of combination meter

• Damaged wiring harness and connectors

• 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

STEP 1. Using scan tool MB991958, read the diagnostic 
trouble code.
Check if DTC B2415 is set to the KOS-ECU.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect 

scan too (M.U.T.-III) 

P.42B-10

."

(2) Turn the ignition switch to the "ON" position.
(3) Check if DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC B2415 set?

YES : Refer to 

P.42B-118

.

NO :  Go to Step 2.

STEP 2. Using scan tool MB991958, read the combination 
meter diagnostic trouble code.
Check if DTC is set in the combination meter.
Q: Is the DTC set?

YES : Troubleshoot the combination meter. (Refer to 

GROUP 54A, Diagnosis 

P.54A-28

).

NO :  Go to Step 3.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

DIAGNOSIS

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-189

STEP 3. Using scan tool MB991958, read the KOS-ECU 
trouble code.
Check if DTC is set to the KOS-ECU.
Q: Is the DTC set?

YES : Refer to 

P.42B-20

.

NO :  Go to Step 4.

STEP 4. Check of the troubles.
Check that the keyless operation warning display turns OFF 
unless the flashing or illumination conditions are met.
Q: Does the warning display operate properly?

YES : 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

).

NO :  Replace KOS-ECU and register the ID codes. (Refer 

to 

P.42B-12

).

DIAGNOSIS

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-190

Inspection Procedure 5: IG knob will not turn (keyless operation is not recognized).

CAUTION

Before replacing the ECU, ensure that the com-
munication circuit is normal.

KOS-ECU System Circuit

KOS-ECU

JOINT
CONNECTOR (6)

KEY
REMINDER
SWITCH

WHEN
REMOVING
KEY: ON

(PUSH SWITCH)

ETACS-ECU

FUSIBLE
LINK

36

RELAY
BOX

KEYLESS
OPERATION
KEY

IMMOBILIZER
ANTENNA

RECEIVER

RECEIVER ANTENNA
ASSEMBLY

RECEIVER ANTENNA
MODULE