Mitsubishi Evolution X. Manual — part 141

SYSTEM CONSTRUCTION

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-19

DATA LIST OUTPUT

.

The following items can be read by the scan tool
from the occupant classification-ECU input data.

ACCURACY CHECK OCCUPANT CLASSIFICATION SENSOR

The scan tool can be used to perform the next func-
tion.

• seat weight sensor Accuracy Check

• Zero-calibration

Item No.

Display on M.U.T.-III

Check condition

Normal condition

01

Passenger weight

Apply a load to the passenger
seat.

Load equivalent to passenger
seat crew member load

02

Dr seat position sensor
current

Slide the seat the back-end to
the front-position.

0 to 1,700 mA

03

Dr seat position sensor
voltage

Slide the seat the back-end to
the front-position.

0 to 5,000 mV

07

Dr seat position sensor
status

Slide the seat the back-end to
the front-position.

Not in Frontal Zone/In Frontal
Zone/Undetermined

08

occupant classification
status

Apply a load to the passenger
seat.

Empty/RFIS/Child/More
5th%/Undermined

10

Battery voltage

Always

6.5 to 16 V

21

Pa seat weight sensor 1
RR

Apply a load to the passenger
seat.

Load equivalent to passenger
seat crew member load

22

Pa seat weight sensor 1
RR volt

Apply a load to the passenger
seat.

0 to 5,000 mV

23

Pa seat weight sensor 2
RF

Apply a load to the passenger
seat.

Load equivalent to passenger
seat crew member load

24

Pa seat weight sensor 2
RF volt

Apply a load to the passenger
seat.

0 to 5,000 mV

25

Pa seat weight sensor 3
LF

Apply a load to the passenger
seat.

Load equivalent to passenger
seat crew member load

26

Pa seat weight sensor 3
LF volt

Apply a load to the passenger
seat.

0 to 5,000 mV

27

Pa seat weight sensor 4
LR

Apply a load to the passenger
seat.

Load equivalent to passenger
seat crew member load

28

Pa seat weight sensor 4
LR volt

Apply a load to the passenger
seat.

0 to 5,000 mV

30

VIN Information

Always

−

SYSTEM CONSTRUCTION

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-20

SEAT BELT WITH PRE-TENSIONER

M2521008000515

The seatbelt pretensioner automatically winds the
seatbelt at the frontal collision to restrain the forward
travel of the passenger. The seatbelt pretensioner
operates in ahead of the SRS airbag deployment to
restrain the forward travel of the passenger at the
frontal collision, for achieving the effective SRS air-
bag.

SEATBELT PRETENSIONER OPERATION

1. When the pretensioner is inactivated, the clearance

between the roller and the sleeve is secured, and thus the
sleeve rotates freely. The spool which winds the seatbelt
rotates together as with the sleeve.

AC709223

Piston (Rack gear)

Spool

Cap

Pinion
(Pinion gear)

Sleeve

Roller

Gas generator

Case gear

Base cartridge

Plate cover

Bushing

Piston ring

Spiral spring unit

AB

AC105418

Clearance

AC

Roller

Sleeve

SYSTEM CONSTRUCTION

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-21

2. At the frontal collision, SRS-ECU which has detected the

impact exceeding the threshold from the front impact
sensors is energized to ignite the gas generator. Then the
gas is generated, and the gas pressure moves up the piston.

3. When the piston moves up, the integrated rack gear of the

piston is engaged with the integrated pinion gear of the
pinion to rotate the pinion. When the pinion rotates, the
pinion is tilted to move the roller to the center, and the
pinion, sleeve, and spool are incorporated.

4. The gas pressure moves up the piston farther, and the

pinion rotates the spool to wind the belt.

AC105077

:Force direction

Connection

AC

Gas generator

Piston

Sleeve

Pinion

Roller

Pinion gear

Rack gear

AC105078

AC

Rotates with spool

:Force direction

SYSTEM CONSTRUCTION

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-22

PASSENGER SEAT BELT WARNING LIGHT

M2521001500036

The passenger's seat belt warning light turns ON when the pas-
senger's seat occupant is determined to be 66 lbs (30 kg) or
more by the occupant classification-ECU and his seat belt is
not fastened.

PASSENGER'S AIR BAG OFF INDICATOR LIGHT

M2521001600055

The indicator normally comes on when the ignition switch is
turned to the "ON" position and goes off a few seconds later.
In the following situations, the indicator will stay on to show that
the passenger’s (front) air bag is not operational.

• The occupant is determined to be less than 66 lbs (30 kg)

by the occupant classification-ECU.

• The front passenger’s seat is not occupied.

The indicator goes off when the occupant is determined to be
66 lbs (30 kg) or more by the occupant classification-ECU, indi-
cating that the passenger's (front) air bag is operational.

SRS-ECU

M2521007000749

The SRS-ECU incorporates a front analog G-sensor
and front safing G-sensor for frontal collisions and a
side-airbag safing G-sensor for side collisions.
SRS-ECU enters an ignite signal to the driver's and
passenger's (front) air bag modules if the front
impact sensor in the engine compartment, the front
analog G-sensor and front safing G-sensor in the
SRS-ECU simultaneously detect gravitational impact
upon front impact. Further, SRS-ECU starts an ignite
signal for the side and curtain air bag module upon
sideways gravitational impact that is simultaneously
detected by the analog G-sensor of the side impact
sensor and the side-airbag safing G-sensor inside
the SRS-ECU.

The SRS-ECU is provided with the following capabil-
ities:

• Backup power supply in case of power failure in

collisions

• Boosting function in case of battery voltage drop

• Self-diagnosis function to avoid system’s opera-

tion errors and improve its reliability

DIAGNOSTIC FUNCTION

The SRS-ECU has the following functions to make
system checking using the scan tool easy.

• Diagnostic trouble code output

• Service data output

• Actuator test

AC608501

Passenger's seat belt
warning light

AB

AC608501

Passenger's air bag OFF
indicator light

AC