A warning symbol keeps on showing on my BMW 318i 2002 model. It's like a seat with a balloon in front. I assume it's the front airbag, but what's the problem and how can I fix it?

Have you checked the dash dimmer switch to see if it's on fully?

Do you have the correct bulbs? Did you check to see whether any of the other front lights are out? I don't know which instrument panel you have but have a walk around the car with the lights on and see if any of the lights are actually out..

check for code to find the problem.

prob the passenger occupancy seat sensor mat, common fault on the e46, happened to my 320ci o4 plate, around 200 pound to fix, but could go wrong again.

you need the scanner to diagnose this problam if no scanner needed then it will be on http://www.vehix411.com all for free how to diagnose the airbag all in video and also how to reset it without a computer cheak it out it might help you

Malfunction indicator light it is the symbol of your engine with a line of suffering and the word "CHECK" -- this could be something minor like needing a spark plug to be replaced (common problem) or to something more serious like engine electrical work needed. a flashing engine light is the more serious so you are not to worry.
keep this handy: http://www.newbeetle.org/forums/2-0-liter-gas/39141-where-can-i-find-warning-light-diagram.html

if the light does not go off there is somthing wrong they might have to replace the seat belts the seat belts have triggers in them when you get in an accident the triggers go off and they need to replace

simply open the boot & remove the blown bulb & replace with a new one. the bulb is just a half turn holding in there so turn it anticlockwise & it should pop out.

more than one plug disconnect or a ground problem

You need diagnostic software that can scan for BMW codes other than engine codes. This will tell you which airbag is triggering the fault light. If you have side airbags that are built into the seats, like I do on my Audi A4, you may have the same issue that I do with mine - moving the seat a little too far pulls on the airbag connector under the seat, separating it just enough to trip the fault light. I zip-tied mine tightly to keep it from separating, and then used the diagnostic computer to turn off the light. Most of the time an airbag light will not reset itself - it has to be manually turned off using a scanner or other interface software and a computer. If you don't have this, you'll probably have to pay someone to do it for you, but make sure to find the suspect bag first and see what you can do to keep it from triggering a light again.