Mitsubishi Evolution X. Manual — part 137

GENERAL INFORMATION

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-3

SYSTEM COMPONENT PARTS

The SRS consists of driver’s and passenger’s (front)
air bag modules, knee air bag modules, side-airbag
modules, curtain air bag modules, SRS-ECU (air bag
control unit), front impact sensors, side impact sen-
sors, SRS warning light, passenger’s air bag OFF
indicator light, passenger’s seat belt warning light,
clock spring, seat belt pre-tensioner, seat belt switch,
seat slide sensor, occupant classification-ECU and
weight sensor. Driver’s and passenger’s (front) air
bag modules are located in the center of the steering
wheel and above the glove box. The knee air bag
module has been installed to the instrument panel
lower section under the steering column.Side-air-
bags are located inside the front seatback frame.
The curtain air bag module has been installed onto
the roof side section (from front pillar and back end of
rear pillar).Each air bag consists of a folded air bag
and an inflator unit. The SRS-ECU placed on the
forefront of the floor monitors the system and has a
front air bag safing G-sensor, front air bag analog
G-sensor and a side-airbag safing G-sensor. The
front impact sensor is assembled in the front end

upper bar to monitor impact in case of front impact.
The side impact sensors inside the center pillars
monitor the shock incurred by the sides of the vehi-
cle. The SRS warning light on the combination meter
indicates the operational status of the SRS. The
clock spring is installed in the steering column. The
seat belt pre-tensioner is built into the driver's and
passenger's front seat belt retractor. The seat slide
sensor is installed at the seat adjuster section of the
driver seat in order to detect the driver seat slide
position. The weight sensor is installed underneath a
rail of the passenger seat to detect the load on the
seat. The occupant classification-ECU mounted
under the front passenger's seat determines the
occupant class according to the signals from the
weight sensors and sends signals to SRS-ECU.The
passenger’s air bag OFF indicator light is installed to
the lower left of the center panel, and illuminates
when the passenger’s (front) air bag is inactive. The
passenger’s seat belt warning light is installed to the
lower right of the center panel, and illuminates when
the passenger is not wearing the seat belt. The seat
belt switch detects whether the seat belt is used.

AC709183

Driver's air bag

Passenger's (front) air bag

Side-airbag

Curtain air bag

Seat belt with
pre-tensioner

AB

Knee air bag

GENERAL INFORMATION

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-4

The SRS-ECU will start a squib ignition current to the
driver's/passenger’s (front) air bag module, knee air
bag module and seat belt pre-tensioner when simul-
taneously detecting frontal impact with the front
impact sensor, front air bag safing G-sensor and
front air bag analog G-sensor. It will also supply a
squib ignition current to the side-airbag module and
curtain air bag module when simultaneously detect-
ing side impact with the side impact sensor and
side-airbag safing G-sensor.

GENERAL INFORMATION

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-5

CONSTRUCTION DIAGRAM

AC708198

AC100836

Curtain air bag module

Side impact sensor

Side-airbag module

Front impact sensor

SRS-ECU

Driver's air bag module

Clock spring

Passenger's (front)
air bag module

Diagnosis
connector

AC

SRS warning light

SRS warning light

<Vehicles for USA>

<Vehicles for CANADA>

Knee air bag module

Seat belt pre-tensioner

Occupant
classification-ECU

Seat slide sensor

Weight sensor

Passenger's seat belt warning light

Passenger's air bag OFF indicator light

Vehicle
identification
code chart plate

Weight sensor

Seat belt
pre-tensioner

GENERAL INFORMATION

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-6

SRS SYSTEM CIRCUIT DIAGRAM

AC708943

ON

OFF

OFF

OFF

ON

ON

ON

OFF

ON

OFF

ON

OFF

ON
OFF

OFF

OFF

ON

ON

ON

OFF

ON

OFF

ON

OFF

OFF

ON

OFF

ON

ON
OFF

ON

OFF

OFF

ON
OFF

ON

ON

OFF

ON

OFF

OFF

ON

OFF

ON

OFF

ON

OFF

ON

ON

OFF

ON

OFF

ON
OFF

ON

OFF

ON
OFF

ON

OFF

ON

OFF

ON

OFF

ON

ON

OFF

ON

OFF

ON

OFF

ON

OFF

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

Cloc

k spr

ing

Driver's air bag module

Passenger's (front)
air bag module

Side-airbag module
(LH)

Side-airbag module
(RH)

Seat belt pre-tensioner
(RH

Seat belt pre-tensioner
(LH)

Knee air bag module
(Driver's side)

Curtain air bag module
(LH)

Curtain air bag module
(RH)

ON

OFF

ON

OFF

ON

OFF

ON

OFF

SRS-ECU

Front impact sensor
(RH)

Front impact sensor
(LH)

Side impact
sensor (LH)

Side impact
sensor (RH)

AB

Note
* : Connector lock switch
Connector connected: ON
Connector disconnected: OFF

Date link connector
(For scan tool)

Can bus line

Combination meter,
Front seat assembly

Seat belt switch
(Passenger's side)

Passenger's air bag
OFF indicator light

No.
18
7.5A

No.
12
7.5A

ETACS-ECU

Ignition switch (IG1) Fusible link