Mitsubishi Evolution X. Manual - part 93

SYSTEM OPERATION

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-21

TIRE PRESSURE MONITORING SYSTEM (TPMS) FUNCTION

M2421000600022

When the tire pressure becomes under the specified 
value, the TPMS function warns the driver of that 
state by illuminating the TPMS warning light.

OPERATION

• The signals from the TPMS transmitter are 

received by the receiver antenna assembly and 
sent to KOS-ECU.

• KOS-ECU processes input signals from each 

TPMS transmitter as well as vehicle speed sig-
nals from the ABS-ECU. It receives the atmo-
spheric pressure signal from ECM, and when the 
atmospheric pressure is low (such as at high alti-
tude), it calibrates the tire pressure received from 
TPMS transmitter and makes a judgment of 
warning. When the road tire pressure is low, it 
sends a warning signal causing the TPMS warn-
ing light to be illuminated. When the TPMS has 
problems, it sends a warning signal causing the 
TPMS warning light to be flashed

*

.

NOTE: 

*

: Change to continuous illumination after 

flashing for about 1 minute.

• For 3 seconds after the ignition switch is turned to 

the "ON" position, KOS-ECU illuminates the 
TPMS warning light to check any breaks in the 
TPMS warning light circuit.

• By connecting the scan tool to the data link con-

nector, data stored in KOS-ECU (data of tire 
pressure and TPMS transmitter ID, the alarm sta-
tus and warning history, etc.) can be displayed 
and TPMS transmitter ID can be registered.
NOTE: If the TPMS transmitter is replaced, regis-
ter the ID codes of all the TPMS transmitters 
again using the scan tool.

TPMS WARNING LIGHT

The TPMS warning light on the combination meter illuminates 
or flashes

*

 to alert the driver by request from KOS-ECU. When 

the tire pressure warning or the fault warning is activated, a 
warning symbol and a message are displayed on the multi 
information display.
WARNING DISPLAY PATTERN OF TPMS WARNING LIGHT 
AND MULTI INFORMATION DISPLAY

NOTE: 

*

:Change to continuous illumination after flashing about 

1 minute.

Circumstance

Warning light Multi 

information 
display

For 3 seconds 
after the ignition 
switch is turned to 
the "ON" position 
(warning light 
circuit self-check)

Illuminates

No indication

TPMS problems

Flashes

*

Symbol and 
"SERVICE 
REQUIRED" is 
displayed

Low tire pressure Illuminates

Symbol and 
"LOW TIRE 
PRESSURE" 
is displayed

LOW 
   TIRE PRESSURE

SERVICE 
           REQUIRED

AC609362

SYSTEM OPERATION

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-22

TIRE PRESSURE THRESHOLD VALUES

TPMS TRANSMITTER (TIRE PRESSURE SENSOR)

The TPMS transmitter combines the valve and tire 
pressure sensor in a single unit. The TPMS transmit-
ters are mounted inside the tires. The TPMS trans-
mitter measures tire pressure directly with its tire 
pressure sensor and sends radio frequency signals 
to KOS-ECU via receiver antenna assembly. The 
TPMS transmitter includes acceleration sensor that 
senses tire rotation, and change tire pressure sam-
pling and data transmission timing when vehicle is 
running.
NOTE: Use only genuine wheels. The use of 
non-genuine wheels may cause the improper instal-
lation of the TPMS transmitters, possibly resulting in 
air leakage and damage to the TPMS transmitter.

.

TIRE PRESSURE SAMPLING TIMING

NOTE: Vehicle moving = vehicle speed: approxi-
mately 25 km/h (15 mph) or more

.

DATA TRANSMISSION TIMING

If a sampled pressure varies by 

±10 kPa 

(1.5psi) from the last transmitted pressure 
value, an additional transmission will occur.

NOTE: 

*

: Once every 15 seconds for first 30 trans-

mission after vehicle starts moving.

Item

Tire pressure kPa (psi)

Standard pressure at 
cold (reference)

220 (32)

Alarm ON pressure

174 (25.2) or less

Alarm OFF pressure

189 (27.4) or more

Vehicle status

Sampling timing

At vehicle moving

once every 5 seconds

At vehicle stationary

once every 1 minute

Vehicle status

Transmission timing

At vehicle moving

once every 1 minute

*

At vehicle stationary

once every 13 hours

SYSTEM OPERATION

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-23

WARNINGS/ALARMS

M2421009300181

If the KOS failed, operated improperly, KOS-ECU 
warns the driver of this by setting off the outer tone 
alarm and the keyless operation warning indicator, 
on the multi information display in the combination 
meter. If the TPMS fails or the tire pressure is low, 
KOS-ECU warns the driver of that state by the TPMS 
warning light and the multi information display in the 
combination meter.

Display 
contents

Item

State

Warning operations

Warning 

cancellation 

conditions 

(Cancels warning 

operations when 

one of the 

conditions met)

TPMS 
warning 
light

Multi 
information 
display

Low keyless 
operation key battery 
voltage warning

The keyless 
operation key 
with low battery 
voltage is 
detected when 
the IG knob is 
pressed.

−

• Warning 

indicator 
flashes for 
30 seconds.

• The outer 

tone alarm 
will not 
sound.

• IG knob in 

"LOCK" (OFF) 
position and 
push switch OFF 
are detected.

• 30 seconds have 

passed after the 
warning output 
started.

No keyless operation 
key detected inside 
the car

No keyless 
operation key is 
detected inside 
the car when the 
IG knob is 
pressed.

−

• The warning 

indicator 
flashes for 5 
minutes.

• The outer 

tone alarm 
will not 
sound.

• IG knob in 

"LOCK" (OFF) 
position and 
push switch OFF 
are detected.

• 5 minutes have 

passed after the 
warning output 
started.

IG knob is not 
returned properly.

Opening of the 
driver's door is 
detected when 
the IG knob is in 
ACC or LOCK 
position and the 
push switch is 
ON.

−

• The warning 

indicator 
flashes for 5 
minutes.

• The outer 

tone alarm 
will not 
sound.

• Key 

reminder 
warning tone 
alarm 
sounds until 
closing of the 
driver's door 
is detected.

• The IG knob in 

the "RUN" or 
"START" 
position, or the 
IG knob in the 
"LOCK" (OFF) 
position, and the 
push switch OFF 
are detected.

• The driver's door 

is detected 
closed from the 
open position.

• 5 minutes have 

passed after the 
warning output 
started.

AC610126

KEY BATTERY 
                        LOW

AB

AC610127

KEY MISSING

AB

AC610124AB

STEERING
     WHEEL LOCK

SYSTEM OPERATION

TSB Revision

KEYLESS OPERATION SYSTEM (KOS)

42B-24

Keyless operation 
key brought out of 
the car warning

The keyless 
operation key is 
carried out of 
the vehicle 
when the IG 
knob is in the 
position other 
than the LOCK 
position, and all 
the doors are 
closed.

−

• The warning 

indicator 
flashes for 5 
minutes.

• Outer tone 

alarm 
sounds for 
5.69 
seconds in 
pattern 2.

• IG knob in 

"LOCK" (OFF) 
position and 
push switch OFF 
are detected.

• KOS-ECU has 

detected a 
keyless 
operation key 
inside the 
vehicle.

• 5 minutes have 

passed after the 
warning output 
started.

Door lock does not 
operate.

Push switch is 
pressed ON 
when the IG 
knob is in other 
than LOCK 
position.

−

• Warning 

indicator 
flashes for 5 
seconds.

• Outer tone 

alarm 
sounds for 
2.96 
seconds in 
pattern 1.

• IG knob in 

"LOCK" (OFF) 
position and 
push switch OFF 
are detected.

• 5 seconds have 

passed after the 
warning output 
started.

Push switch is 
pressed ON 
when the 
keyless 
operation key is 
inside the car.

• Lock switch on 

the keyless 
operation switch 
is pressed again.

• 5 seconds have 

passed after the 
warning output 
started.

Push switch is 
pressed ON 
when the door is 
ajar.

• All doors are 

closed.

• 5 seconds have 

passed after the 
warning output 
started.

Display 
contents

Item

State

Warning operations

Warning 

cancellation 

conditions 

(Cancels warning 

operations when 

one of the 

conditions met)

TPMS 
warning 
light

Multi 
information 
display

AC610128

CONFIRM
    KEY LOCATION

AC

AC610129

CHECK DOORS

AB