Gen 4 Prius Issues

Nobody has been answering questions that the OP has raised. Well ok, statements he has made about his Prius. Typically a lemon doesn't make it 60,000 miles. About the high reving sound. You or your lady most likely put the Prius in B mode instead of D mode. the downhill regenerative braking mode is what makes what you call that loud engine revving sound.

As far as the other issues. I cannot comment.

 

I don't think that the OP, having had the car for 100,000kms would have suddenly started using "B" Mode - it's not something you're going to select by accident.

But it did cross my mind that the OP's PRIUS maybe inadvertently using something like "B" mode - not selected by the driver, but as a fault - possibly in relation to the Software Update which @Elektroingenieur has suggested.

The last 3 weeks, mine has been acting very differently, quite often, despite a full battery it has been telling me "EV MODE UNAVAILABLE" and also revving the engine on the over-run going down hills, which I rarely had before. The big difference with mine is that is has had almost no change in fuel use. But I'd put it down to a very different driving route / routine (my Mum's been in hospital so my commute now includes regularly visiting her).

But I've had no power loss. Nor problems with BlueTeeth (despite my unreliable antique Samsung S2 being almost ready for the grave)

 

It must be Spring down there Alan. As the temperature rises for you the engine will spin up to assist in regulating the hybrid battery from overheating from charging. BTW, my ICE sometimes spins up before the battery level gets to the last bar while charging. Somebody on here said it can do that for a few different reasons. Perhaps we're all liable to overthinking these Gen 4 operating systems. I'm tempted to just ignore the anomalies unless they seem dangerous. Kinda like Momma know best, where Momma is the Prius!

 

I had scan gauge constantly hooked up, for maybe the first four years with our 2010, and was getting check Hybrid system warning, brake warning and return-to-default brake performance. At suggestion of dealership mechanic (he noticed intermittent connection interruption while checking with techstream) I stopped SG use about 3 years back, and aforementioned behaviours have not returned.

That's one thing, but you seem to have a WACK of issues. Good luck, hope you get resolution.

 

to the OP, i will add though that my prius when going downhill fast on a straight about 90kmh in D mode and a 80% charged hv battery in summer seems to rev the engine high that i thought it was faulty. but when i switched from D to B mode the engine revs went even higher. so i'd say the computer seems to know what its doing.