Airbag

What is a airbag
Airbag (SRS=secondary restrict system (primary is seat belt) is a safety feature in a car to stop the driver/passenger from hitting their head against the wind screen,steering or dash board. Late vehicles comes with multiple airbag this includes curtain airbags for driver,front and back passenger

How it works

How it works is basically a explosion ( of nitrogen gas) happens in the bag and the bag holds the explosion inside this inflates the bag to acts as a force against the force of the driver/passengers moving forward. The curtain airbag works the same, it is hidden in the side pillar.There is capacitors inside the ECU to keep the air bag working  this is so that if something happens to the battery and you have a crash  the air bag still works (disconnect both wires positive and negative of battery the longer the better so the capacitor discharge if need to disable airbag
The passengers seat has a sensor so that the air bag  don't go off  if there's no one in the seat.

For the airbag to work all sensors must be trigger, 2 front shock sensors(normally open switch sensor) in series and 1 in the ECU,all 3 sensor has to close in series. Ones the sensor switch is close it cant be open you have to replace them.


2 Types of Air bag system
mechnical = dont have light
electrical = dash board light 7 seconds until the light goes off


To test airbag
Use a dummy resistor (eg usually2 oh use 2R2ohm not all air bag is 2 ohm ) connect to the wire ,connect the battery and  if  the dash light goes off then you know its the airbag that the fault
or swap the passenger with the driver. (don't ever use a multimeter to check the ohm of the airbag, the airbag will go off.)
yellow/orange colour of loom (not wire) for airbag