Mitsubishi Evolution X. Manual - part 139

SYSTEM OPERATION

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-11

SIDE AND CURTAIN AIR BAGS

M2521000800357

SRS-ECU uses data of the side impact sensor and 
G-sensor (in SRS-ECU) to calculate collision sever-
ity, during side collision. SRS-ECU judges necessity 
of side-airbag and curtain air bag based on the cal-
culated collision severity.

AC709200

Side impact 
sensor 
(front: RH)

Side impact 
sensor 
(front: LH)

Shock 
above a 
certain 
level

Ignition signal

Ignition judgment

G-sensor (Side-airbag, 
curtain air bag)

SRS-ECU

Curtain air bag modules

Side-airbag modules

AB

Side impact against another vehicle

SYSTEM CONSTRUCTION

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-12

SYSTEM CONSTRUCTION

DRIVER'S SIDE AIR BAG MODULE

M2521002000539

The driver’s air bag module incorporates a 
three-spoke steering wheel. The driver’s air bag 
module is an assembly part consisting of an air bag, 
inflator, and their fasteners. The air bag is made from 
nylon and inflates by gas from the inflator. As a driver 
is being pressed to the air bag, it deflates discharg-
ing gas from two vents at the rear of the air bag to 

reduce the shock from the impact. The driver's air 
bag deploys by changing its inflation pressure in two 
steps. The inflator has two squib connectors to 
deploy the air bag in two steps. For the inflator, the 
gas which is harmless to the human body has been 
adopted.

CLOCK SPRING

M2521001100083

The clock spring consists of a flat cable, rotator, stator, Roller, 
etc. The flat cable is loosely wound in the case in coil-form. 
One end is attached to the rotator and the other end is attached 
to the stator. By turning the steering wheel, the clock spring 
rotator turns along with the steering shaft. The flat cable is 
wound or unwound by the rotator according to how the steering 
wheel turns. It must be in the neutral position when assembling 
the clock spring.
NOTE: For the clock spring centering procedures, refer to the 
SERVICE MANUAL.

AC709202

A

A

AB

Section A - A

Inflator

Driver's air bag

Driver's air bag module

AC709130

Rotator

Flat cable

Stator

AB

Roller

SYSTEM CONSTRUCTION

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-13

PASSENGER'S (FRONT) AIR BAG MODULE

M2521002100149

The passenger’s (front) air bag module consists of 
an air bag, and their fasteners.
The air bag is made from nylon and inflates by the 
gas from the inflator. As a passenger is being 
pressed to the air bag, it deflates, discharging gas 
from two vents at the side of the air bag to reduce the 
shock from the impact.
The front passenger’s air bag deploys by changing 
its inflation pressure in two steps.

The inflator has two squib connector to deploy the air 
bag in two steps.
The front passenger air bag does not deploy at the 
front passenger seat is not occupied and when the 
occupant classification sensor in the front passenger 
seat senses a weight on the seat of less than 66 
pounds (30 kg).
For the inflator, the gas which is harmless to the 
human body has been adopted.

KNEE AIR BAG MODULE

M2521002600070

The knee air bag consists of the air bag, inflator, and 
fixing gear relating to those parts, and is installed 
onto the instrument panel lower under the steering 
column.
At the frontal collision, the knee air bag deploys by 
the gas generated from the inflator to protect passen-
ger's feet (knee and leg). Like the air bag for frontal 

collision, the knee air bag are made of nylon whose 
inside is rubber-coated, and is folded up and housed 
in a cover. Gas exhaust openings are provided at the 
sewed sections of the air bag to reduce the impacts 
on the passenger's feet at deployment.
For the inflator, the gas which is harmless to the 
human body has been adopted.

AC609452

AC608598

Air bag module

Air bag

Squib connectors

Inflator

AB

AC709204

AC608525

AB

Section A-A

A

A

Inflator

Air bag

Cover

SYSTEM CONSTRUCTION

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-14

SIDE-AIRBAG MODULE

M2521004000364

The side-airbag module consists of an air bag, air 
bag cover, inflator and their fasteners. The modules 
are installed in the outer side supports of the driver’s 
and front passenger’s seatbacks. The side-airbags 
help protect the occupants regardless of the seat 
position and seatback angle.

The side-airbag made of nylon fabric. The air bags 
are compactly folded and stored under the cover. On 
the side of the air bag, there are holes through which 
gas is partially released to alleviate shock to the 
occupant when the air bag is deployed. For the infla-
tor, the gas which is harmless to the human body has 
been adopted.

CURTAIN AIR BAG MODULE

M2521000500312

The curtain air bag module consists of an air bag, an 
inflator, and the fixing gear relating to those parts, 
and is installed in the roof side sections (from the 
driver's and the passenger's front pillars to the rear 
pillars).

The air bag is made from nylon with the inside 
coated with silicon, and housed in the roof side sec-
tions, folded up compactly.
For the inflator, the gas which is harmless to the 
human body has been adopted.

AC709209

Air bag module

AB

AC608585

Curtain air bag module

Inflator

AB