[Cheburashka]

There have been a lot of patrols on the six-mile road I drive in on every morning, so I started using cruise control to keep my speed at 36. For the past couple of days, the cruise control has been keeping the speed at 36 on the flats, but hasn't been controlling the upper speed. Going down hills, my speed can get up to 44 MPH--and of course, the dude with the radar is at the bottom of the hill.

Anyone have this problem? Anything I can do to fix it? The dealer is 300 miles from here.

Thanks

 

[trm2]

Drive in L, that should keep the speed downhill.

 

[Steverino]

Yes, try cruise control in Low.

 

[Cheburashka]

I tried that, and it doesn't make a difference. It seems like, at least on my car, cruise overrides low. There's no difference between L and D with the CC engaged.

 

[hellsop]

Is the slope the *very first thing* you encounter on the road, or it does it come after a few miles of driving?

 

[ClarksonCote]

I tried that, and it doesn't make a difference. It seems like, at least on my car, cruise overrides low. There's no difference between L and D with the CC engaged.

"L" should work, as long as you're not immediately starting down a hill. Does driving in "L" never slow you down? Maybe something is wrong with your regen...

"L" will use regen to keep your speed at whatever is set by the cruise control, even on hills, unless they're very steep. On a road where you're going 38mph I would expect you to have no problem keeping your speed with L.

As hellsop posed, is your hill at the very beginning of your drive? If so the battery may not be able to accept any more energy, if you started off with a full battery. But that is not very likely, especially if you already accelerated to some speed and then encountered these hills.

 

[Norton]

Right, it should work in L.
The Volt has a '2 mode CC' because in D it will let the speed increase on downhills. In L it will Regen to maintain the set speed.

I miss this feature on my Spark EV. It locks on to the set speed and regens a lot to maintain it in D.
I have never found a hill steep enough to go faster than the set CC speed.

 

[Cheburashka]

Right, it should work in L.
The Volt has a '2 mode CC' because in D it will let the speed increase on downhills.

???

It appears you're right, but that seems goofy to me. From the manual:

"When going up steep hills,
you might have to step on the
accelerator pedal to maintain the
vehicle speed. When going
downhill, you might have to brake or
shift to a lower gear to maintain the
vehicle speed. When the brakes are
applied the cruise control is
disengaged."

So it appears that what happens is that the CC scrubs speed by engaging the regen. If the hill is too steep, the regen can't handle all the excess power, so the car will accelerate. It doesn't matter whether you're in L or D. Once you run past the regen's power to scrub off speed, you'll accelerate.

 

[DonC]

I think it's a little different. When going downhill CC simply doesn't apply any acceleration. At this point the car applies the amount of regen you've specified for this situation as a default. If in "L" you have more regen. If in "D" you have less. Works the same way without CC active. Try it. When you go down a hill switch from "D" to "L" or vice versa.

 

[Cheburashka]

I think it's a little different. When going downhill CC simply doesn't apply any acceleration. At this point the car applies the amount of regen you've specified for this situation as a default. If in "L" you have more regen. If in "D" you have less. Works the same way without CC active. Try it. When you go down a hill switch from "D" to "L" or vice versa.

I don't know how I can say this more clearly. I have tried it. I have shifted between L and D while going down a steep hill in CC, and there is no change in my speed. There is no added resistance. The car continues in exactly the same way it did before, as though I hadn't moved the shifter.

Are you saying that yours behaves differently when going down a steep hill?

 

[Cheburashka]

Right, it should work in L.
The Volt has a '2 mode CC' because in D it will let the speed increase on downhills. In L it will Regen to maintain the set speed.

I can't find any mention anywhere of a dual mode CC which changes how the car behaves when going down hill. Where would I find this written up?

 

[Barry]

My 13 will absolutely hold speed within about 2 mph or better down steep hills in L with cruise control active.

Be sure to select L before your speed builds up. You can keep it in L the whole drive if you like. Once your speed has built up and you then shift into L, the regen comes on very gradually and it will seem like it is not working right away.

 

[ItsNotAboutTheMoney]

Cruise control can only do what your accelerator pedal can do. So L allows it to apply greater regen.
But even L has its limits and if you're dealing with very steep downhill slopes you'd need occasionally to use the brake. And, of course, once you've used the brake you have to resume.

And just to double-check, when you move the shifter to L do you actually see the car shift to L on the display?

 

[Norton]

I can't find any mention anywhere of a dual mode CC which changes how the car behaves when going down hill. Where would I find this written up?

Ha,ha, normally my response is RTFM, but evidently this subject is not mention in the Fabulous Manual.

If you're saying your car definitely does not regen a lot more on downhills in L and CC engaged? Oh Well....
Mine did. And I started thinking of the CC as having '2 modes'.

Good luck having this issue looked at by a dealership...
Could it be some years operate differently?

 

[Cheburashka]

Cruise control can only do what your accelerator pedal can do. So L allows it to apply greater regen.
But even L has its limits and if you're dealing with very steep downhill slopes you'd need occasionally to use the brake.

Works for me. Sounds like the car is working as it should, and it's just a matter of a hill that's steep enough to override the regen.

 

[hellsop]

I don't know how I can say this more clearly. I have tried it. I have shifted between L and D while going down a steep hill in CC, and there is no change in my speed. There is no added resistance. The car continues in exactly the same way it did before, as though I hadn't moved the shifter.

Are you saying that yours behaves differently when going down a steep hill?

Yes, that is exactly what we are saying. L applies more regen than D, when foot is removed from the accelerator. That's its job, that's what it does/should do. The cruise control works by releasing the accelerator when the car's speed is above its setpoint, and that triggers the regen braking effect to keep the car at the right speed. L, since it applies more regen than D, brakes harder than D and should be sufficient for about a 4% grade. D alone might not be -- that'll hold a speed to about a 1% grade, but not much more than that.

If your car does not, then it's probably time to go visit the dealership and get it fixed.