2001 Toyota Rav4 transmission slipping when coasting

You need to get a transmission specialist to run a few tests, check codes and line pressures, check turbine rations for slippage.

MIL is not on so no codes to call out. Well line pressures will be checked. However, could the same reason be why transition between 2 and 3 and sometimes 3 to 4 harsh? This is an automatic transmission system, just an additional information.

Thank you.
'Yinkebo

You can still have codes set without a MIL activated, get the scan first.

I had this problem on my 2002. I chased down transmission error codes and was about to replace some solenoids. Then, I walked into the local Toyota service center, described my problem and the two service techs looked at each other, then at me and said, in unison, "It's your computer". Turns out that the computer was giving only 8 volts to the transmission solenoids that require 12 volts to fully actuate. So, one computer and $1,500.00 dollars later, my Rav shifted just fine. FYI there is a service bulletin on this. Should've been a recall.
Hope this helps.

Thank you for the input Rowen, it is always a good idea to start looking at the electrics first so a code read is very important.