Yep. I had same issue and, including NX200t. Last one had horrible CC operation going downhill.
Word of wisdom - don't use it for that purpose.Particularly, on crazy hybrid system.

 

Just to add.. ICE is not really "working" rolling down the hill in hybrids. It is used as air brake to slow down vehicle, by engine mass resistance and VVT-i operation of valves, bleeding air out. No petrol supplied to ICE.

 

This is perfectly normal. My 2018 Camry Hybrid has been doing this off and on since it was new.

You pretty much nailed it when you said "I assume this is done to cause a gearing change within the eCVT so as to create an engine braking effect." And rightly so. The 2.5 L engine in the Camry hybrid has a very high compression ratio of 14:1, so why wouldn't Toyota take advantage of all that compression to slow the car down. I have a 06 PT Cruiser GT that automatically downshifts a gear to help slow it down when going down steep hills while on cruise. So why wouldn't Toyota use the far more advanced eCVT to dial up a similar "gear" ratio to slow down the Camry by compression under cruise control. Now the question is, why is it so intermittent?

So here's the deal. Normally, the hybrid system would use the regenerative braking to slow the car down when descending steep hills under cruise. And it in fact does,.. most of the time. However, when the traction battery has reached a state of full charge, the generator can no longer keep charging it. Therefore, the regenerative braking ceases working to prevent overcharging. So the system resorts to its next best tool it has in its bag of tricks, engine compression. That's why you don't hear it all the time even on the same exact hill. It's only going to do it when the battery is full and regenerative braking isn't an option. And don't worry about the engine sounding like it's revving too high. Toyota isn't going to let the car do anything that can harm it. Mine revs up pretty high too sometimes. It can be startling sometimes because we don't often hear these engines rev up much unless we're passing someone very quickly or aggressively merging into traffic.

So just let it do it's thing and rest assured it's working as it should.

 

This is perfectly normal. My 2018 Camry Hybrid has been doing this off and on since it was new.

You pretty much nailed it when you said "I assume this is done to cause a gearing change within the eCVT so as to create an engine braking effect." And rightly so. The 2.5 L engine in the Camry hybrid has a very high compression ratio of 14:1, so why wouldn't Toyota take advantage of all that compression to slow the car down. I have a 06 PT Cruiser GT that automatically downshifts a gear to help slow it down when going down steep hills while on cruise. So why wouldn't Toyota use the far more advanced eCVT to dial up a similar "gear" ratio to slow down the Camry by compression under cruise control. Now the question is, why is it so intermittent?

So here's the deal. Normally, the hybrid system would use the regenerative braking to slow the car down when descending steep hills under cruise. And it in fact does,.. most of the time. However, when the traction battery has reached a state of full charge, the generator can no longer keep charging it. Therefore, the regenerative braking ceases working to prevent overcharging. So the system resorts to its next best tool it has in its bag of tricks, engine compression. That's why you don't hear it all the time even on the same exact hill. It's only going to do it when the battery is full and regenerative braking isn't an option. And don't worry about the engine sounding like it's revving too high. Toyota isn't going to let the car do anything that can harm it. Mine revs up pretty high too sometimes. It can be startling sometimes because we don't often hear these engines rev up much unless we're passing someone very quickly or aggressively merging into traffic.

So just let it do it's thing and rest assured it's working as it should.

Thanks guys. I stand enlightened.

The only thing that's puzzling me now is, how I managed to be oblivious to this behaviour for the first two years of ownership. Hmm... must learn to pay more attention.

Regards

 

Engine braking is not done by gear changing as there are no gears in PSD. Well, there are, but not gear gears, just epicyclic gear set.
Engine braking is accomplished by locking ICE to PSD via MG, no fuel supplied to ICE, while VVT-i closes and opens valves to control air flow through cylinders. Basically, controlled air compression in cylinders is used to create braking effect.

 

Another factor, I would postulate, would be my driving style. I used to baby the car in the first year or so of ownership. New car shyness, if you will. For the past 6 months, however, I've been less shy and have been putting my foot down a bit more. Used to drive exclusively in ECO mode, but am more of a NORMAL mode driver these days... with the occasional use of SPORT mode if I'm in a good mood.

Maybe tyre wear is another factor.

But, I digress... I appreciate the education received on this matter.

On a side note, I would really love it if the Highlander Hybrid (which we call Kluger) would make it down-under. My experience with Toyota's Hybrid system has been extremely positive to-date, and I am already considering my next Hybrid purchase. With the kids growing, I don't think the rear quarters of this Camry will serve them for much longer.

Thanks again to all.