This is fairly repeatable, on the new-to-me 2017 ILX (love it): I'm on ACC, feels like it's working well, and then I accelerate briefly with the foot-pedal. The ACC turns off. It does not "cancel" or "suspend" - it turns off. Well ... it does not respond. The ACC icon remains visible. "Resume" has no effect. "Decelerate" will lower the set speed, shown numerically on the display, but it doesn't actually work, and that field goes blank again shortly after I stop adjusting with the buttons. I have to cycle the "Main" button and start the process all over again.

I have looked through the list of things which can cancel the ACC, and it's possible that there are things in there. But I looked through the list of things which can turn it right off, and I don't think that those conditions apply.

The behaviour is like "Cancel" except that it will not "Resume".

Is this normal?

Thanks.

 

You might have a problem. I'm pretty sure the ACC is supposed to suspend, then resume automatically after you let go of the gas pedal. I would bring it in. You can also request they drive a new car on their lot to confirm your car is not working properly.

 

Yes, thanks. I will ask about it at the dealer perhaps this autumn. I'm still I think under some of sort of "certified-used" Acura warranty.

I am a little fearful of further mayhem, once someone starts delving into modern car-electronics!

 

Update: I believe the system to be behaving normally and that it always was behaving normally.

The owner's manual says this (page 358):
So, being used to conventional "cruise control", that seemed clear enough.

It isn't.

With conventional cruise control, the set speed remains on and one can coast back down to the set speed, with or without some degree of application of the accelerator pedal.

With the Adaptive Cruise Control, ACC, once the accelerator pedal is in use, e.g. to pass a vehicle responsibly quickly rather than just crawl past, the ACC suspends and the little speed indicator on the dashboard (multi-information display) disappears, until ... the pedal is released.

In other words, one can coast down in speed and way past the set speed, without the system "resuming", if there is still some depression of the accelerator pedal.

Release the pedal, and the ACC resumes, the set-speed number pops back on, and it begins working again.

None of this was intuitive or predictable to me, and having had a seventh look at the owner's manual, the instructions remain obscure to me as well.

Anyway, it's all fine, as long as this behaviour of the ACC system is normal.

Sorry for the false alarm.

 

This is also true of conventional cruise control. You can test it out by switching over to conventional cruise by holding down the ACC "set distance" button.

 

My first thought, schen72, was "nah," but I tested it and you're right. It also explains the puzzling cruise control "malfunction" of our 2012 RDX. I have sold a 2009 TL but don't recall it behaving this way.

So, I got in my other car, a N. Am. vehicle, and that explains why I thought I knew what was going on, and never made the mental transition to the Acura paradigm. In my Chev, like all of the other cars I have owned over 40 years, the car stays on "cruise" even with the accelerator in manual ("pedal" but ignore that) operation, and will not decelerate below that number whether the foot is lifted or whether it remains applied during deceleration. I say "so at least I'm not completely losing my mind," or least, "that's not evidence of same".

The 2017 ILX owner's manual's inscrutable statement now makes more sense:
"There are times when the vehicle speed will decrease when the accelerator pedal is lightly applied."

But it is inscrutable. It means, assuming I now understand how it works, "The ACC or cruise-control suspends when the accelerator pedal is applied and will not resume until the foot is entirely off."

Thanks again.