Mitsubishi Evolution X. Manual - part 524

GENERAL INFORMATION

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-3

CONSTRUCTION DIAGRAM

AC709242

AC506891

AC506892

AC611960

AC709237

ECM

Exterior transmitter
antenna assembly
(Driver's side)

Antenna and tone alarm assembly
<Exterior transmitter antenna 
assembly (Trunk lid), 
Outer tone alarm>

KOS-ECU

ETACS-ECU

AB

Steering lock 
(Push switch, 
Steering lock unit)

IG knob cap

Lock switch and Unlock sensor

(Driver's side door, Passenger's side door)

Unlock sensor

Lock switch

Lock switch and
Unlock sensor
(Passenger's side door)

IG knob

Receiver
antenna module

A

A

Section A - A

Unlock
sensor

Front door
outside
handle

Door
assembly

Lock switch and
Unlock sensor
(Driver's side door)

Exterior transmitter
antenna assembly
(Passenger's side)

Interior transmitter
antenna assembly (Rear)

Interior transmitter
antenna assembly (Front)

TPMS transmitter
(Tire pressure sensor)

TPMS transmitter
(Tire pressure sensor)

TPMS transmitter
(Tire pressure sensor)

TPMS transmitter
(Tire pressure sensor)

Trunk lid
opener switch

ASC-ECU

Reciever antenna assembly

Ignition switch

Front of vehicle

GENERAL INFORMATION

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-4

.

AC709248

SERVICE

         REQUIRED

LOW

  TIRE PRESSURE

Multi information display
(Built in combination meter)

TPMS
warning light

AB

AC613563AD

Emergency key

Emergency key

Keyless operation key

Emergency key

Lock button

Unlock button

Indicator light

Trunk lid button

Panic button

GENERAL INFORMATION

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-5

Main components and functions

Parts name

Functional description

KOS-ECU

Controls KOS by using the following inputs/outputs and 
communications.

• Input from the unlock sensor and lock switch on each door, 

input from the push switch on the IG knob

• Communications with ETACS-ECU, ECM or ASC-ECU and 

combination meter via CAN

• Wire communication with the steering lock unit

• Wireless communication with the keyless operation key via 

the receiver antenna module, receiver antenna assembly 
and interior/exterior transmitter antennas

• Wireless communication with the TPMS transmitter

• Output to the outer tone alarm

Steering lock (incorporates push switch 
and steering lock unit)

The steering lock has two unlocking mechanisms; a mechanical 
mechanism that uses an emergency key and an electrical 
mechanism. In the electrical unlocking mechanism, the steering 
lock communicates with KOS-ECU via wire, and when 
requested by KOS-ECU, the steering lock unlocks for two 
seconds.

Keyless operation key (incorporates 
emergency key)

• The keyless operation key receives signals sent from each 

interior/exterior transmitter antenna, certifies the keyless 
operation key ID code, calculates the key ID, and sends the 
reply data signal to KOS-ECU via the receiver antenna 
assembly. The lock button, unlock button, and trunk lid 
button operations of keyless operation key transmit signals 
to KOS-ECU via the receiver antenna assembly.

• If two or more keyless operation keys registered in 

KOS-ECU respond at the same time, their signals would 
interfere. To avoid this interference, each signal from 
KOS-ECU is given the priority

*1

 data, and the keyless 

operation keys respond in accordance with this priority.

Lock switch

Driver's door

Locks all the doors when a driver carrying the keyless operation 
key presses the lock switch on the front door outside handle. 

Front passenger's 
door

Unlock sensor

Driver's door

The unlock sensors incorporated in the driver’s front door 
outside handles unlock driver’s the door when a driver carrying 
the keyless operation key pulls the driver’s door outside handle. 

Front passenger's 
door

The unlock sensors incorporated in the passenger's front door 
outside handles unlock all the doors when a driver carrying the 
keyless operation key pulls the front door outside handle. 

Trunk lid opener switch

By pressing the trunk lid opener switch on the trunk lid while 
he/she is carrying the keyless operation key, the trunk lid is 
unlocked. 
NOTE: With the locking of trunk lid, the locking is performed 
mechanically when the trunk lid is closed.

Exterior transmitter 
antenna assembly

Driver's side

Converts the data output from KOS-ECU via wire into a signal, 
and sends it to the keyless operation key.

Front passenger's 
side

GENERAL INFORMATION

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-6

NOTE: 

*1

: When registering the keyless operation 

keys, KOS-ECU numbers each key (1 to 4) in the 
order they are registered (initial priority). This priority 
is renewed each time the doors are locked/unlocked 
and the IG knob is pressed. For example, when only 
keys 1 and 3 have responded to the signal sent from 
KOS-ECU, the new priority of the keys would be 
1-3-2-4. When keys 3 and 4 have responded, then 
the priority of the keys becomes 3-4-1-2.

NOTE: 

*2

: Illuminates for tire pressure warning. 

Flashes for about 1 minute and then continuously 
illuminated for TPMS malfunction warning.

.

Interior transmitter 
antenna assembly

Front

Converts the data output from KOS-ECU via wire into a signal, 
and sends it to the keyless operation key.

Rear

Antenna & tone 
alarm assembly

Exterior transmitter 
antenna assembly 
(trunk lid)

Converts the data output from KOS-ECU via wire into a signal, 
and sends it to the keyless operation key.

Outer tone alarm

The outer tone alarm sounds when:

• The doors are locked or unlocked by the door entry function.

• The lock switch on the keyless operation switch is pressed 

when the IG knob is in the "LOCK" (OFF) position and the 
push switch is in other than the "ON" position.

• The lock switch is pressed on the keyless operation key from 

inside the car.

• The lock switch on the keyless operation key is pressed 

when the door is ajar.

Receiver antenna module

Receives the keyless operation key ID data from the keyless 
operation key which is needed for the engine start, and then 
outputs the data to KOS-ECU.

Receiver antenna assembly

Receives the operation signals from the lock/unlock buttons, 
trunk lid button, and panic button on the keyless operation key 
as well as the keyless operation key ID data which is necessary 
for engine start and the tire pressure signal from the TPMS 
transmitter. Then, sends the data to KOS-ECU.

TPMS transmitter

Measure tire pressure directly, then send radio frequency signal 
to receiver antenna assembly.

Combination meter (Multi information 
display, TPMS warning light)

Communicates with KOS-ECU via CAN. Receives the warning 
request or warning information from KOS-ECU, activates

*2

 the 

warning light. Warning symbol and message is additionally 
displayed on the multi information display

ETACS-ECU

Communicates with KOS-ECU via CAN. By the door 
lock/unlock request, trunk open request, or panic alarm request 
from KOS-ECU, ETACS-ECU outputs the lock/unlock signal, 
trunk open signal, or panic alarm signal. When the door 
lock/unlock signal is output, ETACS-ECU flashes or illuminates 
the turn signal light and dome light to notify that the lock/unlock 
operation is performed.

ECM

Communicates with KOS-ECU via CAN. Permits/inhibits the 
engine starting and controls the engine operation. Send 
atmospheric pressure data.

ASC-ECU

Communicates with KOS-ECU via CAN. Sends the vehicle 
speed data.

Parts name

Functional description