Component Description
| Component | Function |
|---|---|
| Air bag diagnosis sensor unit | Detects a collision and supplies power supply for deployment to air bag module 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. |
| BCM | Receive the collision detection signal when air bag diagnosis sensor unit detects collision. |
| Combination meter (air bag warning lamp) | Indicates air bag malfunctioning and deployment by blinking and illuminating air bag warning lamp. |
| Combination switch (spiral cable) | Supplies power supply to driver air bag module on steering wheel. |
| Crash zone sensor | Transmits signal to air bag diagnosis sensor unit when a frontal collision occurs. Crash zone sensor is a G sensor that outputs voltage signal during deceleration at the time of a vehicle frontal collision that is more than the specified limit is detected. |
| Curtain air bag module LH/RH | Deploys according to collision judgment of G sensor, pressure 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 setting limit of the vehicle. Gas is generated by chemical reaction of ignition material, passes filter, and deploys air bag. Air bag module mainly consists of air bag and inflator that deploys air bag. |
| 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. |
| Front door satellite sensor LH/RH | 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" sensor, 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. |
| Occupant detection system control unit | Detects front passenger seat occupant. |
| 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. |
| Passenger air bag OFF indicator | Indicates whether or not passenger air bag is in the activation mode based on the judgement of occupant classification system. |
| Satellite sensor LH/RH | 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" sensor, 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 and curtain air bag and seat belt pre-tensioner. |
| Seat belt buckle switch LH/RH | Controls deployment timing depending on the seat belt condition that is fastened or unfastened. |
| Seat belt pre-tensioner LH/RH | Receives signal from air bag diagnosis sensor unit and deploys seat belt pre-tensioner and lap pre-tensioner. In the case of a frontal collision or side collision that exceeds specified 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. |
| Side air bag module LH/RH | 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. |
Scheme 1
System 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.
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 deceleration 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.
Description
| CAUTION | Never use electrical test equipment on any circuit related to the SRS unless instructed in this Service Information. SRS wiring harnesses can be identified by yellow and/or orange harnesses or harness connectors. Never repair, splice or modify the SRS wiring harness. If the harness is damaged, replace it with a new one. Keep ground portion clean. |
ZERO POINT RESET DESCRIPTION
This vehicle adopts occupant detection system with a weight detecting method. When replacing, or removing and installing passenger seat, always perform "zero point rest" 1 so that the vehicle recognizes zero point.
If zero point reset is incomplete, occupant detection seat sensor does not operate normally.
ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT: Description
When replacing or removing and installing passenger seat, always perform zero point reset so that Occupant Detection System is activated normally.
Zero point reset is an initializing procedure for occupant detection sensor that must be performed when replacing or removing and installing passenger seat.
If zero point reset is not performed, the initialization is incomplete and Occupant Detection System does not operate normally.
Note. When replacing passenger seat with a NISSAN genuine part, air bag warning lamp blinks if zero point reset is incomplete. When zero point reset is performed once after removal and installation of passenger seat, CONSULT displays "complete" and air bag warning does not blink. When reinstalling passenger seat after removal, the initial value for occupant detection sensor changes, and Occupant Detection System does not operate normally. Always perform zero point reset after performing the work as per the following. Reinstallation of passenger seat Replacement of passenger seat with a seat that is zero point reset complete.
Suppresses the deployment of front passenger air bag when the condition of passenger seat is empty or occupied with a child and child-seat. Also illuminates front passenger air bag OFF indicator lamp when the condition of passenger seat is occupied with a child-seat and child. In case of malfunction the blinking of the air bag warning lamp reports the malfunction to driver, and by the on board self-diagnosis system or CONSULT can detect the cause.
OPERATION
This unit classifies occupant in passenger seat and detects electrical malfunction in Occupant Detection System and transmits malfunction information to air bag control unit.
The air bags and seat belt pre-tensioners for driver and passenger are activated by the air bag diagnosis sensor unit signal transmitted at the time of the frontal collision.
The side air bag and curtain air bag are activated by the air bag diagnosis sensor unit signal transmitted at the time of side collision.