Nissan Quest E52. Manual — part 1120

COMPONENT PARTS

SRC-9

< SYSTEM DESCRIPTION >

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No.

Component

Function

1.

Driver air bag module

• Receives signal from air bag diagnosis sensor unit and deploys air bag.
• In case of frontal collision where acceleration is more than the specified level,

the ignition materials are ignited by electric ignition system. The system burns
the gas generating materials resulting in a chemical reaction. This generates
hot gases that flow into the air bag through a filter and expand the bag.

2.

Combination switch (spiral cable)

Supplies power supply to driver air bag module on steering wheel.

3.

Combination meter (air bag warning
lamp)

Indicates air bag malfunctioning and deployment by blinking and illuminating air
bag warning lamp.

4.

Passenger air bag OFF indicator

Indicates whether or not passenger air bag is in the activation mode based on
the judgement of occupant detection system.

5.

Passenger air bag module

• Receives signal from air bag diagnosis sensor unit and deploys air bag.
• In case of frontal collision where acceleration is more than the specified level,

the ignition materials are ignited by electric ignition system. The system burns
the gas generating materials resulting in a chemical reaction. This generates
hot gases that flow into the air bag through a filter and expand the bag.

6.

BCM

Receive the collision detection signal when air bag diagnosis sensor unit detects
collision.
Refer to

BCS-4, "BODY CONTROL SYSTEM : Component Parts Location"

for

detailed installation location.

7.

Crash zone sensor

• Transmits signal to air bag diagnosis sensor unit when a frontal collision oc-

curs.

• Crash zone sensor is a G sensor that outputs voltage signal during decelera-

tion at the time of a vehicle frontal collision that is more than the specified limit
is detected.

8.

Air bag diagnosis sensor unit

• Detects a collision and supplies power supply for deployment to air bag mod-

ule and pre-tensioner seat belt.

• It contains the “G” sensors for both frontal and side collisions and spare battery

function in case of main battery damage in collision.

9.

Front door satellite sensor LH

• Transmits signal to air bag diagnosis sensor unit when a side collision occurs.
• When air bag diagnosis sensor unit defines both signal voltage of the “G” sen-

sor, pressure sensor and the safing algorithm to be that of collision which is
more than the specified level, the driving circuit switches on and feeds the
electric ignitor of both the side air bag, curtain air bag and pre-tensioner.

10.

Seat belt pre-tensioner LH

• Receives signal from air bag diagnosis sensor unit and deploys seat belt pre-

tensioner.

• In the case of a frontal collision or side collision or roll over that exceeds spec-

ified impact level, the air bag diagnosis sensor unit detects the deceleration
caused by collision. It restrains the passenger with seat belt easing the stress
on passengers chest with load limiter.

11.

Front satellite sensor LH

• Transmits signal to air bag diagnosis sensor unit when a side collision occurs.
• When air bag diagnosis sensor unit defines both signal voltage of the “G” sen-

sor, and the safing algorithm to be that of collision which is more than the spec-
ified level, the driving circuit switches on and feeds the electric ignitor of both
the side air bag and curtain air bag and seat belt pre-tensioner.

12.

Rear satellite sensor LH

• Transmits signal to air bag diagnosis sensor unit when a side collision occurs.
• When air bag diagnosis sensor unit defines both signal voltage of the “G” sen-

sor, and the safing algorithm to be that of collision which is more than the spec-
ified level, the driving circuit switches on and feeds the electric ignitor of both
the side air bag and curtain air bag and seat belt pre-tensioner.

13.

Seat belt buckle switch LH

Controls deployment timing depending on the seat belt condition that is fastened
or unfastened.

14.

Side air bag module LH

• Receives signal from air bag diagnosis sensor unit and deploys air bag.
• In case of side collision where acceleration is more than the specified level, the

ignition materials are ignited by electric ignition system. The system burns the
gas generating materials resulting in a chemical reaction. This generates hot
gases that flow into the air bag through a filter and expand the bag.

SRC-10

< SYSTEM DESCRIPTION >

COMPONENT PARTS

15.

Rear curtain air bag module

• Deploys according to collision judgment of G sensor, and safing sensor.
• Receives collision signal from air bag diagnosis sensor unit, ignites, and burns

ignition material by electric ignition system, when side collision exceeds set-
ting limit of the vehicle. Gas is generated by chemical reaction of ignition ma-
terial, passes filter, and deploys air bag.

• Air bag module mainly consists of air bag and inflator that deploys air bag.

16.

Front curtain air bag module

• Deploys according to collision judgment of G sensor, and safing sensor.
• Receives collision signal from air bag diagnosis sensor unit, ignites, and burns

ignition material by electric ignition system, when side collision exceeds set-
ting limit of the vehicle. Gas is generated by chemical reaction of ignition ma-
terial, passes filter, and deploys air bag.

• Air bag module mainly consists of air bag and inflator that deploys air bag.

17.

Occupant detection system control unit

Transmits the passenger seat status (occupied or empty) to air bag diagnosis
sensor unit.

18.

Occupant detection system sensor

Transmits the passenger seat status (occupied or empty) to occupant detection
system control unit.Itis installed in the passenger seat cushion frame.

No.

Component

Function

SYSTEM

SRC-11

< SYSTEM DESCRIPTION >

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SYSTEM

System Description

INFOID:0000000009649842

SYSTEM DIAGRAM

DESCRIPTION

Supplemental Restraint System (SRS) activates air bag module and seat belt pre-tensioner when it detects a
frontal collision or a side collision that is more than the specified limit.

JMHIA2032GB

SRC-12

< SYSTEM DESCRIPTION >

SYSTEM

Together with other safety devices, it reduces the impact that occupant receives when vehicle collision occurs.
Air bag diagnosis sensor unit supplies power supply to air bag module and pre-tensioner seat belt when decel-
eration that is more than the specified limit is detected by G sensor in air bag diagnosis sensor unit, crash
zone sensor, satellite sensor, or front door satellite sensor.
Air bag module is composed of electric igniter (squib), filter, pyrotechnic material, and gas generating material.
When air bag module receives a signal from air bag diagnosis sensor unit, air bag module ignites pyrotechnic
material using electric igniter (squib) so that gas generating material generates high temperature nitrogen gas.
The gas through filter activates air bag. At the same time, pre-tensioner seat belt receives power supply from
air bag diagnosis sensor unit, gas generator is activated, and then gas is generated.
Balls in pipe are moved according to generated gas pressure and strike pinion gear on ELR shaft.
ELR shaft rotates and retracts seat belt.

AIR BAG DIAGNOSIS SENSOR UNIT FUNCTIONS

Air bag diagnosis sensor unit has the following functions.
• Detects a collision and supplies the energy for deploying air bag and seat belt pre-tensioner.
• Detects and records electrical malfunction in air bag system and seat belt pre-tensioner system, and blinking

air bag warning lamp.

• Detects and records the deployment of air bag and seat belt pre-tensioner, and turns ON air bag warning

lamp.

• Indicates malfunctioning portion via the number of blinks from the air bag warning lamp in the diagnosis

mode.

• Indicates the malfunction record via CONSULT.
• Suppresses the deployment of passenger air bag when passenger seat is empty or occupied by child or

child-seat.

• When passenger seat is occupied by child or child seat, turns ON passenger air bag OFF indicator.
• When judges that passenger seat is occupied by a adult or a child and passenger seat belt is not fasten,

turns ON seat belt warning lamp. Further information for the seat belt warning system.

• When collision is detected, collision signal is transmitted to BCM (collision detection function).

COLLISION MODES

The operation of SRS is different depending on the collision modes applications.
SRS configurations that are activated for the following collision modes.

×

: Apply —: Not apply

OCCUPANT DETECTION SYSTEM

This Occupant Detection System has the following functions.
1.

Suppress the deployment of front passenger air bag when front passenger seat is empty, or when occu-
pied by child and child-seat. Turns ON front passenger air bag OFF indicator when front passenger seat is
occupied by child-seat and child.

2.

Indicates malfunction portion with blinking times of air bag warning lamp in diagnosis mode.

3.

Indicates the malfunctioning record by CONSULT.

4.

When “zero point reset” for occupant detection system is incomplete, CONSULT indicates that “zero point
reset” is incomplete.
This function is applied to NISSAN genuine parts only.

NOTE:

SRS configuration

Frontal collision

Left side collision

Right side collision

Driver air bag module

×

—

—

Passenger air bag module

×

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Seat belt pre-tensioner LH

×

×

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Seat belt pre-tensioner RH

×

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×

Side air bag module LH

—

×

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Side air bag module RH

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×

Front curtain air bag module LH

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Front curtain air bag module RH

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×

Rear curtain air bag module LH

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×

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Rear curtain air bag module RH

—

—

×