abs and trac lights

went to start car this a.m. and abs light came on and stayed on and trac on and trac off lights came on, trac on light went off as usual but trac off stayed on whats up with this any ideas? car was fine the previous p.m. thanks for any ideas. it is a 99 300m

A fault was found in the ABS system during its self check. Have the ABS system scanned for trouble codes.

A fault was found in the ABS system during its self check. Have the ABS system scanned for trouble codes.
Thanks airjer , yep right rear wheel speed sensor. i guess trac and abs system are integrated so got a quote for 130.00 and ill be good to go again thanks for reply