When temperature surpasses 90 degrees inside car (especially while sitting parked while I'm at work) I have problems getting shifter to stay in gear. When I shift in D or R the shifter immediately shifts back to neutral. I found I can hold the shifter in the desired direction and the car goes like normal. I tried a test of leaving windows slightly open and found the car cooler inside and the gear shift problems did not occur. The dealership says the gear shift is electronic, no gears. Is there a switch for this under the panel by the gear shift? Has anyone else had this issue? I have a 2008 Prius, that I recently purchased used. My wife has a 2005 Prius that we purchased new and have never had an issue like this.
The gear shifter lever always returns to the center point. I assume you know that, which means that your question is not about the shifter, but about the car not staying in D or R. This problem is normally caused by a failing shifter switch assembly, which is the little shifter lever and its associated parts. It's fairly easy to replace; instructions can be found on this website. Alternately you can pay the dealer to replace it. Tom
*Really easy to replace* Autobeyours.com has the part. I thought I would have to replace the part in my car when it acted up last year, but oddly enough after two events similar to OP's report, it has been fine.
I have the exact same problem, and I am wondering if this problem is covered by the 8 years guarantee on the HSD system? Don't know if you have the same in the US, but we have that in France, so if I can get the part changed for free that would be nice... Thanks! Eric