When you have a "check engine light" (CEL) indication, I believe three lights appear, including the two you mentioned. The chances are that you have a CEL event. You need to borrow a CEL code reader (AutoZone) or purchase one (Costco) and give us the code(s), if any. For me, it has always been an airflow or Oxygen sensor that caused a CEL event. This is not uncommon on all newer cars, not only the RX300.
You need to determine exactly what lights are on before you can proceed. If you have the CEL on in addition to the 2 lights you mentioned proceed as bob2200 sugested above. If not I suspect you need to do a zero point calibration, which was a common problem with 2001. Read the attached link plus all the links within for more info on zero point calibration: http://www.clublexus.com/forums/rx-f...001-rx300.html
Or no matter what lights you have on, you may want to disconnect the negative battery cable for a few minutes and see if you get lucky.