Mitsubishi Evolution X. Manual - part 588

DIAGNOSIS

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-259

STEP 6. Check the wiring harness between the outer tone 
alarm connector F-21 (terminal Nos. 1, 2) and the ground 
for short circuit.
(1) Disconnect outer tone alarm connector F-21, and check the 

wiring harness.

(2) Check the wiring harness between outer tone alarm 

connector F-21 (terminal No. 1) and ground

OK: No continuity

(3) Check the wiring harness between outer tone alarm 

connector F-21 (terminal No. 2) and ground

OK: No continuity

Q: Is the wiring harness between outer tone alarm 

connector F-21 (terminal Nos. 1, 2) and the ground in 
good condition?
YES  : Go to Step 7.
NO [outer tone alarm connector F-21 terminal No.1 

− 

ground.] : Repair the wiring harness between outer tone 

alarm connector F-21 (terminal No.1) and ground.

NO [outer tone alarm connector F-21 terminal No.2 

− 

ground.] : Repair the wiring harness between outer tone 

alarm connector F-21 (terminal No.2) and the ground.

STEP 7. Check of the troubles
Check that the outer tone alarm sounds when the outer tone 
alarm sounding conditions are met.
Q: Is the check result normal?

YES : The diagnosis is complete.
NO :  Replace KOS-ECU and register the ID codes (Refer 

to 

P.42B-12

).

INPUT SIGNAL REFERENCE TABLE

M1429614800011

AC709707IX

Harness side: F-21

AC709707IY

Harness side: F-21

Trouble symptom

Reference page

Signals from transmitter switches are not received.

P.42B-260

DIAGNOSIS

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-260

INPUT SIGNAL PROCEDURES

Signals from transmitter switches are not received.

CAUTION

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

.

TECHNICAL DESCRIPTION (COMMENT)

Input signal from the keyless entry transmitter is 
used to operate the keyless entry system. If the sig-
nal is abnormal, the keyless entry system will not 
work normally.

.

TROUBLESHOOTING HINTS

• Battery discharged in the transmitter

• Malfunction of the transmitter

• Malfunction of KOS-ECU

DIAGNOSIS

Required Special Tools:

• MB992006: Extra fine probe

• MB991223: Harness set

• 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.

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 tool (M.U.T.-III) 

P.42B-10

."

(2) Turn the ignition switch to the "ON" position.
(3) Check whether the KOS-ECU related DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Diagnose the KOS-ECU. Refer to 

P.42B-20

.

NO :  Go to Step 2.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

DIAGNOSIS

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-261

STEP 2. Check the transmitter battery.
Measure the voltage of the transmitter battery.

• The value should be approximately 2.5 - 3.2 volts.

Q: Is the measured voltage approximately 2.5 - 3.2 volts?

YES : Go to Step 3.
NO :  Replace the battery. If the transmitter can be 

registered normally, and operates normally, it 
indicates that the transmitter is sending normal signal 
to the KOS-ECU.

STEP 3. Register the keyless entry secret code using a 
known-normal transmitter of the same type again, and 
check the trouble symptom.
(1) Register a known-normal transmitter of the same type.
(2) Check if the signals from the transmitter switches are 

received.

Q: Can the transmitter be registered correctly?

YES : Replace the original transmitter with a new one.
NO :  Replace the KOS-ECU (Including when the new 

transmitter cannot be registered). Replace KOS-ECU 
and register the ID codes (Refer to 

P.42B-265

). If the 

transmitter works normally, the input signal from the 
transmitter should be normal.

AC004486

DIAGNOSIS

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-262

TERMINAL VOLTAGE REFERENCE CHART

M1429606800232

KOS-ECU TERMINAL CHECK

AC507348

C-05

AJ

Terminal 
number

Check item

Check condition

Normal condition

1

CAN H

−

−

2

CAN L

−

−

3

−

−

−

4

Steering lock unit signal output

When the ignition switch is 
operated

0 to 5 V (pulse signal)

5

Steering lock unit power supply

When the ignition switch is 
operated

5 V

6

Interior transmitter antenna 
assembly (front) ground

Always

0 V

Interior transmitter antenna 
assembly (rear) ground
Exterior transmitter antenna 
assembly (driver's side) ground
Exterior transmitter antenna 
assembly (front passenger's side) 
ground
Exterior transmitter antenna 
assembly (trunk lid) ground

7

Receiver antenna module power 
supply

Always

5 V

Receiver antenna assembly power 
supply

8

Push switch inside the steering lock Push switch inside the steering 

lock: ON

7 to 8 V

9

Receiver antenna assembly DATA 
output

Keyless operation key lock button, 
unlock button, and trunk lid button: 
ON

0 to 5 V (pulse signal)

Receiver antenna module signal 
output

−

10

Receiver antenna module RSSI 
output

−

−

11

Receiver antenna module signal 
output

When communicating with the 
keyless operation key with the 
emergency key inserted in the 
inverted direction (ignition switch: 
ON)

0 to 5 V (pulse signal)