the same problem happened to my 99 taco 4x4, to fix it, i first disconnected my battery and let it sit for one hour (airbag systems have a internal battery that you must let discharge, before you start messing with the system) i then pulled the console under the ash tray and behind it there is the air bag module, it will have some yellow plugs, unplug all of them and plug them back in, this fixed my air bag light, i belive that there was a bad connection in one of the connectors, and by removing it and reinstalling it makes a better connection. Good luck and hope this helps.