cruise control weirdness?

[RayU]

I haven't seen this mentioned elsewhere...

'06 Touring, automatic

We're on a long road trip, zooming across the southwest interstate. Lots of miles using the cruise control. We get to some long hills, and eventually the cruise has to downshift to 3rd to get back up to speed. Okay, a bit of a lurch/surge being that the cruise is set at 75mph. Soon, the car accelerates back up to 75, but it keeps on accelerating in 3rd gear! It's not until after exceeding 80 does it decide to shift back to 4th and stop accelerating.

The first couple of times it did this, I canceled the cruise control, not knowing how long it'd continue to accelerate. It seems to want to continue to charge ahead in 3rd until it's a good 5 - 7 mph above the cruise setting before shifting back to 4th.

Anybody else experience this behavior? Is this considered 'normal'?

 

[jandree22]

I don't know that it's appropriate, but it may be normal. Some cruise controls go whako when you throw a hill at them. The logic may be programmed to compensate for the loss of momentum on a hill, ie, if it would've stopped accellerating and gone back into 4th exactly at 75MPH, it may have not held and dipped below again.

Annoying, sure... but I wouldn't be too concerned about it.

 

[rweatherford]

Yes mine does that on tall hills at slower speeds. I don't like it and tend to not use the CC on hilly terrain.

 

[coolmazda5]

I don't see it on the MTs (duh, really? ) but I've experienced it on several auto rental cars (GM, Chrysler, Nissan). They feel like stuck on the higher gear for several seconds before "releasing" it. During that time the speed oscillates beyond the cruise control setting but then settles, weird.

Pure speculation, but maybe the cruise control thingie is made by the same manufacturer for many car makers and hence the common behavior? (dunno)

 

[antlind]

Mine does the same when it encounters hilly sections of hwy. It holds the 3rd gear for a while and acelerates past the set cruise speed before settling into 4th gear. I usually disable the cruise when I see hilly sections coming and reset it when the hwy flattens out....kinda defeats the purpose of having cruise in the first place.
I have similar issues with my MPV.
Anthony

 

[bulwnkl]

I've experienced this kind of behavior in a variety of cars, both A/T and M/T. I've normally run into it in lower-powered cars, but not always by any means. In all cases where I've spent a few moments to try to figure out what in the world is happening, I've found the same thing:

The cruise-control's control of the throttle is not super-speedy. Thus, when faced with a high-load situation, it ends up lagging a little starting up the hill and then opening the throttle essentially wide open. Then, once it hits target speed, it starts to close the throttle back down. BUT, since it doesn't move the throttle very rapidly, it ends up overshooting target speed by a few to several miles per hour before it gets the throttle closed enough to stop accelerating (and shift back into high in the case of an A/T). Then, it'll close the throttle too far since it knows it's way over target speed, and if the hill's steep enough it'll then drop back below target speed by a few to several mph while it's opening the throttle back up. It can become kind of comical so long as you're not too frustrated by it.

I also shut off the cruise if I'm going into hilly country or just up a long, steep grade. It just makes things smoother.

 

[RayU]

Yeah. I eventually gave up on using the cruise control.

My other cars have been manuals - apparently with enough power that I rarely had a need to downshift while on cruise control. So this was a new experience. My Integra was rock solid on the cruise - very smooth and wouldn't go beyond 1 mph variance. My Protege5, eh, not so smooth, perhap 2+ mph variance. This Mz5 though, geez, the sudden slamming into 3rd, then the dramatic release of the accelerator after flying by the target speed, varying by more than +/- 5 mph...

ick.

 

[rweatherford]

One thing I forgot... If you stick the tranny in M mode it won't downshift into 3rd which makes this problem MUCH less noticable.

 

[jandree22]

Just outa curiosity, if you do shift a gear in M mode in the automatic, will it kick you out of cruise control?

 

[rweatherford]

Not sure. I only use 4th with cruise, but I'll try it sometime.

 

[dfskinner]

When I go out today I'll check.... never tried that....

I do use the cruise and haven't really noticed any issues like those above...... but then again, I don't really drive on too many hills...... Virginia Beach to DC and back is pretty flat......

 

[mrbwa1]

Hey everyone, Cruise does still work if you shift over to M. We have a few trips where we have to do the M3 downshift or else you get the cruise overrun. I have read somewhere before about cruise and M mode not working well, but never had a problem. Note, we don't leave it in M all the time, just flip over into M for the downshift and back to D once the terrain levels out.

You flatland people must really get the good gas mileage. Ever trip I take to visit family involves substantial hills/mountain passes. Thankfully the relatively short gearing of the 5 leaves good power for pulling the hills without too much of a MPG hit.

 

[dfskinner]

yes, I gave it a try, put the car on cruise going approx 45 mph, shifted to "M" on the auto shifter, shifted down from 4th to 3rd gear, cruise continued to stay engaged....... shifted back to 4th, and moved the stick back to auto...... cruise stayed on the entire time; only notice was rpm's went up, but that was expected......

 

[coolmazda5]

I tried with mine but as soon as changed from 4th to 3rd the cruise control got deactivated.... Oh wait, I have MT

LOL, Sorry, I was bored, carry on. FWIW the cruise control light on the 08 is much nice than the 06-07s. You no longer have the 2 lights (yellow "on"
, green "activated"), it is only one and it switches from yellow to green when engaged.

(doh)

My bad, off-topic
(outie)

 

[sensinitas]

Mine does this too, and I like to use the cruise control to keep me at a certain speed since I tend to speed in my 5 for some reason.