i've tested it again this morning. when i start the engine, the Airbag light comes on ONLY when i have a passenger in the front seat. When it's on, it will stay on. The weird thing is IF i turned the engine off(with the passenger still in the seat, wait 20 secs) and started the car again, the airbag light was off and became normal again.
does this mean there's a sensor problem? or airbag problem?