[this guy]

Has anyone else had any issues with the cruise/speed limiter on a GD? Mine seems to subtly surge, as in speed up-slow down-speed up-slow down etc. The dealer updated the ECU today but the problem persists. Very slight, speed doesnt change much if at all, but the car gently rocks back and forth, just enough to be annoying.

[FatBoy]

I had that problem in my FD.  It would only happen at approximately 100 km/h, if I pressed either the ACCEL or COAST button temporarily (i.e. change the speed slightly) the problem disappeared.

[Phil №❶]

Doesn't happen in an auto 

[this guy]

Doesn't happen in an auto 

Quite, because the extra power surge gets sucked up by the torque converter instead of going to the wheels 

[Phil №❶]

 

[this guy]

I am glad that you agree that manuals are more efficient at power transfer and thus superior to autos 

Alas, we digress...

[Phil №❶]

Not superior, just different. Never disagreed about manual efficiency. 

[this guy]

Well you are entitled to your opinion. In the interests of avoiding another manual vs auto argument, I doubt the transmission has a bearing on the cruise problem, at the end of the day it shouldn't be surging. I've done a fair few k's in an FD with cruise, and it never did that at any speed whether it be 60km/h or 110 km/h, and yes, manual of course.

[AlanHo]

My car surges with CC - but only very slightly when on a slight decline where the car cannot seem to make up its mind whether to use the engine or gravity for locomotion.

[this guy]

I will need to try it again on a flat road and on a slight downhill, didn't get too many opportunities driving it home from the dealer, but from the few opportunities I did have, it felt the same as before. Previously it even surged going uphill.

[eye30]

Has anyone else had any issues with the cruise/speed limiter on a GD? Mine seems to subtly surge, as in speed up-slow down-speed up-slow down etc. The dealer updated the ECU today but the problem persists. Very slight, speed doesnt change much if at all, but the car gently rocks back and forth, just enough to be annoying.

Yes

I mentioned this to my dealer not long after i bought my car they gave me a very technical explanation but in lay person speak:
 
In cc mode it is due to you being in a gear not suited to your current road speed.

As an example

In my car i will be doing say 55 in 6th and put on cc.  I get surges.

Now if i speed up to say 65 and put on cc i get no surges.

In above example if at 55 i drop down to 5th gear and put on cc i get no surges.



Ps
I'm sure i posted a similar question some 3 years ago and in that time my car still acts as outlined above so unless anyone has any other explanation i'll stick with the above....

[AlanHo]

Seems plausible - I'll buy that.

[SPman]

Nope..no surging problems..our cruise control just decided to stop working @  95000kms! (turns on..won't set)..........

[cruiserfied]

Have you had your brake switch replaced recently?

[SPman]

Not that I know of.....

[ibrokeit]

cruiserfied may already have PMed about it, but...

Might want to have it checked then - esp. to see if it got replaced as part of the service campaign Hyundai did on the switches (if it wasn't done it could be a free fix to the CC issue).

[this guy]

Has anyone else had any issues with the cruise/speed limiter on a GD? Mine seems to subtly surge, as in speed up-slow down-speed up-slow down etc. The dealer updated the ECU today but the problem persists. Very slight, speed doesnt change much if at all, but the car gently rocks back and forth, just enough to be annoying.

Yes

I mentioned this to my dealer not long after i bought my car they gave me a very technical explanation but in lay person speak:
 
In cc mode it is due to you being in a gear not suited to your current road speed.

As an example

In my car i will be doing say 55 in 6th and put on cc.  I get surges.

Now if i speed up to say 65 and put on cc i get no surges.

In above example if at 55 i drop down to 5th gear and put on cc i get no surges.



Ps
I'm sure i posted a similar question some 3 years ago and in that time my car still acts as outlined above so unless anyone has any other explanation i'll stick with the above....

It's been a while since I brought this up, but I thought I would check back to see if anybody has had a more 'solid' fix other than downshifting e.g. any ECU updates or similar. I have noticed that even if I put it in a lower gear e.g. 60km/h in 4th instead of 5th, it still does the subtle rocking but maybe not to such a great extent, but it's still there, making the use of cruise control (and indeed the speed limiter) quite annoying. Yesterday I was doing about 55km/h in 4th and thought I would try the CC just to see how the surging is going, and just keeps doing it. It's difficult to describe the sound of the engine in words, so lets say the engine makes a 'woo' sound. So driving without cruise control with a steady right foot, it goes wooooooo, a nice consistent drone. Put the cruise or speed limiter on and it goes sort of wooOOOoooOOOoooOOOoooOOO.

Surely this can't be right. The FD's never did this, even if the gear was slighty too high for the given speed. If it is indeed something to do with the computer, I would like to know about it before the warranty runs out. Anyone had any luck or do I just have to resign myself to 'It's just like that, and that's the way it is'?

[xiziz]

Mine did this a lot when I first got it. Now it only does it when cold and doing 80kph in 6th on slight downhills, shifting down to 5th will make it behave. (Or speed up to 85kph).

I've noticed that the car does not really like beeing under 1800 1500 revs, and its most prominent with CC active. The last 10000km i've driven one gear below what previous experience makes feel appropriate: 3rd from 25-50kph, 4th 65kph, 5th up to 85kph and 6th above that. It works well. Car is happier and fuel economy is even slightly better, it probably needs less going uphill(and I drive a lot of them).

Edit: 1500 revs not 1800... Doh