1.2 Tdi cruise control active limits acceleration?

M

maxufeiss

Active Member
Just wired ccs stalk to ECU and during short test drive noticed that when cruise is on, pressing accelerator has very limited effect. As soon as cruise has manually disabled from stalk/brake the car accelerates like it should. Display shows cruise set speed in grey when pressing accelerator (ColorMFA), so car knows i'm pressing it, but does not want to shift down or accelerate much.
Is it normal for 1.2 and i need to learn to live with it?
 
I have working cruise control, ECU reprogrammed during my trip and then installed rest of it myself at home. Was told that installing is all that's left to do, but first try it did not work. Then did activation through vcds coding 11463 and it started working.

Problem is that when cruise has been set, then the car has very limited throttle response. It will do something, but very slowly. Probably will get annoying to pass other cars or getting to higher speed zone and wanting to accelerate. Have to disable cruise, accelerate, set the cruise back on when done.
Thought maybe someone with 1.2 + cruise has same experience or if it works for them. My other audi has no problems accelerating when cruise is on.
 
maxufeiss said:
I have working cruise control, ECU reprogrammed during my trip and then installed rest of it myself at home. Was told that installing is all that's left to do, but first try it did not work. Then did activation through vcds coding 11463 and it started working.

Problem is that when cruise has been set, then the car has very limited throttle response. It will do something, but very slowly. Probably will get annoying to pass other cars or getting to higher speed zone and wanting to accelerate. Have to disable cruise, accelerate, set the cruise back on when done.
Thought maybe someone with 1.2 + cruise has same experience or if it works for them. My other audi has no problems accelerating when cruise is on.
Click to expand...

Over take with the cruise control just hold plus, then hold minus when done ;)


Sent from my iPhone using Tapatalk
 
Made slightly longer trip and observed following:

It does not want to shift down etc. At hills it even loses speed when not enough power but does not shift down. Pressing accelerator to floor forces downshift, but it almost immediately shifts back to higher gear even while i'm keeping it floored. So flooring while doing 90km/h loses speed due to multiple shifts and limited acceleration.
Downhill it won't release accelerator as well, but need to confirm with econ mode (my A8 does not release when climate is on, but climate off will use accelerator off and engine braking as soon set speed is exceeded).
Maybe need to monitor through vcds, but seems like it limits max accelerator position even while manually pressing it.
It will use all Nm engine has to offer (Eco mode), but that does not need flooring anyway.

Holding plus and holding minus is more work than disabling cruise and then resuming where it was set. Especially due to limited acceleration while doing so.
But even with limitations i'm happy to have cruise control, just before installing did a trip involving two 24h and one 15h driving sessions and having to hold pedal constantly is not so fun. It would be even better without those limitations.
At 90km/h acceleration is possible as long downshift is not needed, so some passes can be done with cruise on... But from 50-70 to 90km/h zone changes downshift is best, so can't just resume set speed since then it will try to speed up without changing gear.
 
Sorry to drag this up, but if this is still an issue, or anyone else has this issue, I think I can fix it. As the 1.2 TDI doesn’t have the software switch enabled for cruise control from the factory, I doubt Audi loaded the calibrations associated with how cruise control interacts with the automatic gearbox. So enabling the software switch will allow cruise control to work as you’ve found, but you may get weird behaviour if the calibrations are wrong/missing.

If you can read the flash from your ECU we can have a look and I’ll put a guide together for the forum of how to fix it :)
 
Last edited by a moderator:
I don't have capability to read/write ecu, and probably have gotten somewhat used to it's behavior.
It will try to be in highest gear possible, so now i usually accelerate manually before activating it.
Adjusting the speed is still annoying, since it does not set +/- as i'd expect it to. Trying to input 90 might result in 88-91-91-87-92 etc, aka it does not move by 1 immediately if i move it to +/- direction.
 
maxufeiss said:
Adjusting the speed is still annoying, since it does not set +/- as i'd expect it to. Trying to input 90 might result in 88-91-91-87-92 etc, aka it does not move by 1 immediately if i move it to +/- direction.
Click to expand...
No, the +/- on the A2 cruise control speeds up/slows down the car while you hold it only. So a brief press might get you very little change. You have to hold it at + or - and let go when the car reaches the new speed you want.
 
Mine A2 1.2 tdi has the same behavier, when using cruise control. I dont know if it is possible to add a cancel/pause button and the push the resume button on the stalk, after your acceleration is finished. I dont know if this is possible to implement in the system, this would solve most of My problems with the cruise control
 
Do you have the older stalk, or the newer one where both the + and - are on a rocker switch on the end of the stalk? With that one you can certainly cancel, accelerate, then press + again to set cruise to your new speed (using the - would resume i.e. continue cruise with your previous speed so the car would slow down when you took your foot off the accelerator). I thought the older stalk had a cancel function as well but I could be mistaken.
 
16656871139545824890167026939235.jpg
I have this one, but I dont see how to cancel
 
Pressing the brake pedal or clutch pedal ( manual ) will cancel the cruise automatically. Moving the central switch to off turns off the cruise so you could call that the ultimate cancel button.
 
The vertical bar is a sliding switch. Push it gently to the right, it will cancel cruise and spring back into position. If you want to disable cruise completely, push it all the way to the right until it clicks off.
 
We've been making some good progress is fixing the issues for 1.2 TDI's. Thanks for @Phoenix for testing everything for me. So far we have cruise control working as expected with Ecomatic turned off in software (this also disables tuning the engine off when in the "Stop" position on the gearbox). I've made some more tweaks which should allow it work to with Ecomatic still present, will confirm when the testing has been completed. I will post a guide on how to do everything with explanation once its confirmed. It's very simple if you have the ability to read/write your ECU.
 
Yeah I'm 90% sure I know why this is now, but I don't know why Bosch chose to do it that way. Working on a version now that will hopefully be a compromise to allow it to work better in normal drive. Doubt it will be perfect but should be better than what it is
 
You must log in or register to reply here.
Back
Top