It happened again today. Second time in about 6 months. Leaving a local store I put the car in reverse and nothing happened, car did not move, put in park and back in R, again nothing. Several minutes changing gears in lot and still nothing. Then in R, I pressed the gas and WHAAM! jolted into R and away we go. Scary that this has happened only a couple of times in the last few years. What does it mean? What should I have checked out first?

 

This is not normal behavior. Please have it checked out. Start by checking the fluid level. Operate the RX for min of 15 minutes. Park in a flat horizontal surface and put the gear in Park. Keep the engine running (idling) and check the level.

Salim

 

Welcome to Club Lexus!

Get the transmission fluid changed ASAP! Be sure to use Toyota Type-IV.

 

That happened to me shortly before the transmission failed altogether.