abs fault light.

hi i have just bourght a 2.5 dt range rover 95 ( say just bourght had her 4 mounths got her from an aucction ) . the only thing that seams wrong with it it that yesterday the ABS FAULT light come on. so i stop pulled over swiched her off and then back on and it all was fine it hasent happend again and the brakes are fine. is this someting i should worry about. have cheked the brake fulid leavel and all ok. all so when i start her up i get a buzzing sound from my side under the hood for about 20 seconds then stops and the red ! sign gos out.

any body ?