We no longer call it PBL (problem base learning). It is now called CTS (can't remember what it stands for 😀). They seem to be making small modifications to PBL but nothing major.
And yes it is a mixed of pbl/cts and lectures. We generally only have about 6 hours a week in pbl and the remainder of the time is spent in lecture. PBL/CTS is a part of the curriculum but definitely not the majority.
Check out this link to IUSD which gives a pretty decent explanation of what pbl/cts is.
In summary it is where we get together in groups of 6-8 students and we are presented with a case. We work through the case together making hypothesis and researching information that we are not familiar with. Each case lasts 3-4 sessions. Between each session we have time to research anything that we did not know. We are expected to return to our groups with this information in hand and ready to present (usually informally). 👍
Edit:
As far as I am aware PBL and CTS are the same thing just a different name. The only reason I mention CTS at all is because of OPs question about getting rid of PBL. To clarify once again, at IUSD PBL is now called CTS. Besides the name change I have not noticed any major changes.