Recently laid up for 3 months with a broken ankle. when tried to start my RX 400 battery was totally flat, zero volts, would not take a charge. Returne,d it to EuroCarParts under warranty who replaced it foc. When car restarted had all sorts of flashing lights on dash. Found a local Local garage specialised in Toyota / Lexus. He ran diagnostics which showed problems in every area of mechanics and electronics. Cleared all he codes only one reappeared, ABS sensor fault, broken wire on sensor.
I say don't panic, get codes cleared and start again.