Cold weather cruise control and unexpected engine ON

Adding temperature vs. previous SoC to the bottom of the list to be curious about in this case. Bob win a free pizza? I hear Little Caesar's has a new style...

 

I see an inconsistency here, Bob.

 

It came on for me at 55mph, 20F, and virtually coasting as far as power goes. 97% battery charge.

 

It's 9 F outside and when I started my car the dashboard said 18F went all EV to work, when I arrived the dashboard said 13F

Posted via the PriusChat mobile app.

 

@priuscatprimeguy
Found it it was Bobs thread on off on seem to be working? to cold to tell? Still trying to interest some friends in need of new wheels in the Prime.

 

if you are referring to putting the car in READY then shutting the car off then putting it in READY again. I did that once and You Tubed it. and it seemed to do the trick

 

Labeling a suggested enhancement as a "defect" won't get you too far... especially with Toyota, who uses a business-model of continuous improvement. Take a close look at Tesla's success, who also follows that same approach. The design is what they specified for requirements. Since nothing is actually broken or not working as intended, hence no defect. Instead, you should have submitted it as an improvement idea.

Looking at the other plug-in hybrids, like Hyundai/Kia and Honda, we see differences that completely mess up the rhetoric Volt enthusiasts have been spewing for years. Their mantra falls apart when the business aspect of design is taken into consideration, especially now with those new choices. Then ask why did Toyota make specific choices for this particular release. It comes down to how expectations are set.

"Know your audience" does indeed go both ways. We've witnessed that in the past with Toyota being receptive to owner feedback. For the topic of dynamic-cruise, there was no expectation set for cruising in the suburbs. That's new, a use no one ever mentioned that prior to its availability. Driving with cruise-control anywhere except on the highway was simply unheard off. And since that's what consumes EV the fastest, the expectations was that the engine would be used then anyway.

With the next iteration of design from Toyota, we could the requirement change. Note how Tesla calls those changes to existing vehicles an update. That works great... for them, as a new player exclusive to the EV world. With legacy operation... such as the big traditional vehicle manufacturers, like Toyota... changes after the sale are given a "recall" stigma. So, take into serious consideration about how changes are presented.

Business is much more than just great engineering of hardware & software. Labels make a difference.

 

It is a defect. When the car is in EV mode the engine should not come on until it is ready to change to Hybrid mode or slightly prior.

 

Perhaps a PM to @Prius Team could give some direction. At least tell them about the issue since they are responsible for marketing the Prime in the US.

 

My study of Six-Sigma... which is heavily influenced by Toyota... focuses on continuous improvement.

 

Why? Your purchase was to get top efficiency, not for EV driving under all circumstances. Prime is a plug-in hybrid. It uses the engine from time to time... to protect the battery... to make you warm... to keep fluids fresh.

 

And, how does the engine coming on in EV mode protect the battery? If it cannot run the advertised distance in EV, it is really just a plain ol' hybrid. The Prime has a heat pump to keep you warm.

Bob is not referring to an occasional run to keep the fluids fresh. It is a reproducible bug.

 

I agree this is a bug. Whether you're in cruise or not shouldn't matter, what should matter is throttle position (including regeneration level), battery level (95-99% seems to be the only windows in which this happens, which makes no sense whatsoever), and temperature (I've had it happen from 20F to 56F now, which again makes no sense).

Bug.

 

Advertised? Sounds just like complaints of the past from people who didn't actually read what the window-sticker said.

We're set on educating people. Doing things like provide video-clips for them to observe system operation, just like we witness but take for granted, is a mixed blessing. Think about how many people don't have a clue how their old ICE vehicle actually works. The raising of awareness contributes to a wide variety of "issues" to deal with.

Take a look at ERDTT for Volt. After all these years, that so-called "problem" still exists. Ask why? That condition of "Engine Running Due To Temperature" is a reality, whether you like it or not. GM takes advantage of having an engine available. It's a tradeoff. Providing heat at the low extreme is very expensive, hence the more complex warming system in Bolt.

I don't see plain ol' hybrids offering outstanding MPG in the warmer months for only a small MSRP less. Watch my most recent video and show proof that the tradeoffs Toyota decided upon are not worth it.​

The behavior to make sure the engine is pre-warmed when using cruise below a certain temperature could easily be a safety aspect. You're not paying as close attention when using cruise as when operating the pedal, so the windshield must be guaranteed clear. Calling that a "defect" or a "bug" is refusal to acknowledge the possibility of it being a conscious choice.

As a software engineer, I'd see the complaint ticket and reply back that the system is working exactly as designed. The defect ticket would then be closed, since there's nothing broken. There would be a suggestion for future improvement, since that's what upgrades are for.