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View Full Version : "Slap in the back of the head" take off issues.



lambertia
17-11-2014, 03:14 PM
All,

I am having another problem which is unrelated to ACC. In its most severe case it results in the car lurching off the line and smashing you in the back of the head (so to speak).

It will typically occur when auto hold and stop/start are active. I haven't really nailed down exactly what makes it happen but what follows is an example:

After coming to a halt and removing my foot from the brake the car will shut down. When it's time to move off again I will tap the throttle to get the engine started again and wait until I feel that the car is in gear (I may be lightly feathering the throttle now ready to go - not sure). This seems to take forever (five seconds or so - I don't know why it finds it so hard to find first gear). The car will then start moving with a huge wallop which smacks you in the back of the head - all with little or no throttle.

I'm pretty sure I haven't discovered launch control in the TSI :P.

Has anyone had similar experience?

gldgti
17-11-2014, 03:51 PM
when you come to a stop, wouldnt you usually keep your foot applied to the brake? Even if you are on level ground, I would have thought this is good practice as it alerts anyone behind that your brakes are applied.
This may have something to do with your problem if the car is expecting you to take your foot off the brake and go straight for the accelerator rather than doing whatever you are doing.

lambertia
17-11-2014, 04:01 PM
when you come to a stop, wouldnt you usually keep your foot applied to the brake?

No, this is what the auto hold does - its magic : Auto Hold Function < Technical Glossary < Innovation & Technology < Volkswagen International (http://en.volkswagen.com/en/innovation-and-technology/technical-glossary/auto_hold_funktion.html)

grtuned
17-11-2014, 05:39 PM
It's seems your very aware of the way your systems function which is a good thing. These systems require control by the driver even though they are automated. Do be honest I think your post regarding the roll back is normal. You must press the brake after coming to a stop. The issue you face and it seems you have found a glitch in the system!!
This means you must press the brakes and come to a complete stop for the hill hold to activate then be ready to take off using the accelerator. If you don't this it will roll. If another vehicle does the exact same thing I would consider it a normal function.
As for your take off issue I would at least recommend to have it scanned at a dealership and also you drive while on a demo so you can show the exact issue I hope you find a tech that cares to help.
Volkswagen are a good car I think these issues shouldn't reflect a bad or poor quality vehicle.
Cheers

lambertia
17-11-2014, 06:07 PM
This means you must press the brakes and come to a complete stop for the hill hold to activate then be ready to take off using the accelerator. If you don't this it will roll. If another vehicle does the exact same thing I would consider it a normal function.

This actually isn't true when the ACC is running. It stops the car and applies the brakes and keeps them on. More magic. The excessive roll-back occurs rarely.

Thanks for your feedback. I plan to take it in tomorrow. I also have an annoying rattle right at my ear. That one they will be able to reproduce!

The Bone Ranger
17-11-2014, 06:18 PM
The combination of start/stop and auto-hold takes a little getting used to.

Have you tried driving with the start/stop turned off? I bet you'll find the car is perfectly smooth on take off.

When I first test drove a 90tsi I found that I could have one or the other on in order to drive smoothly, but not both. Since the start/stop takes a moment to start the motor when you take off, the temptation is to bury the accelerator closer to the floor, which is what you'd do in a regular automatic if it didn't respond immediately. In the Golf, this certainly will kick you in the back as you describe.

I think the engine start-up in the Golf isn't the smoothest around; it does cause a solid vibration in the car when it turns over on startup. This, combined with too much throttle input, will certainly get a drivers attention.

I think it's largely a coordination issue. How long have you had the car? It takes a little while to get the feel for all of the electronics.

Try turning the start/stop off for a drive, just to get used to throttle input, and then switch it back on. It made a difference for me.

Andrew.

gldgti
17-11-2014, 06:38 PM
after reading the articvle in the link, I have to ask, do you indeed "brake gently" to a stop? Perhaps if the system is retaining a higher braking pressure during auto-hold it doesnt transition out as smoothly.

GolfVII
18-11-2014, 08:40 AM
I use ACC and Auto Hold all the time and I have found sometimes it will jerk in take off after coming to a stop using ACC but this is only because I jab the accelerator in haste of moving off quickly.

One issue I have noticed is that when you have Auto Hold enabled and you are reversing out a park and when you come to a complete stop then change to Drive it can take a few seconds to select forward and move off with a jolt. Since I back out of a lot of parks lol I have tried doing it with the Auto Hold "OFF" and the gear change is smooth and no jolt... I have come to the conclusion its the Auto Hold causing the delay in changing from R to D. I have gotten used to waiting the 2 sec for the gear to be selected when using Auto Hold.

When I'm using ACC in peak hour traffic I turn the Auto hold off and set to 60 and turn myself in to a lemming, the car stops and holds by itself even though the Auto Hold is turned off.

Saying all this, I have a different engine and drive train to you, but its good to know little bugs I may think are strange do appear on other model cars and if you feel it is not right, ask the dealer like you stated you are. I think my dealer is sick of me but hey I paid them a lot of money so I want support for my product over the period of time they stated they would support it for so its a service I will be taking up at any chance I can.

BCK
18-11-2014, 05:45 PM
Dont get me started.

This is driving me up the wall with my TSi R-Line.

foot off the brake, nothing, then the most massive of forward lurches. HATE IT.

Its got nothing to do with the ACC, as i havent got it fitted and its a constant issue for me.

Its a stop-start issue.

dening
18-11-2014, 09:00 PM
Dont get me started.

This is driving me up the wall with my TSi R-Line.

foot off the brake, nothing, then the most massive of forward lurches. HATE IT.

Its got nothing to do with the ACC, as i havent got it fitted and its a constant issue for me.

Its a stop-start issue.
Yeah a stop start dsg issue. I keep trying to work out a technique to not have it happen...still to no avail. It's the same whether auto hold or not.

pologti18t
19-11-2014, 07:25 AM
Dont get me started.

foot off the brake, nothing, then the most massive of forward lurches. HATE IT.
Its a stop-start issue.

Should the engine restart once it senses you ease off the brake? So, you take your right foot off the brake and apply it to the throttle and you get a lurch?

Hillbilly
19-11-2014, 07:58 AM
I know the Mk 7 system works in better ways than my 3 yr old car but I have found that if I just change pedals too quickly when stop start is engaged it does bound away.

Solution is just to ease off the brake enough for the engine to restart but not allow the car to move and then when traffic moves or lights change you an accelerate normally.
As I mainly drive locally I can anticipate the lights pretty well.

dening
19-11-2014, 08:40 AM
Should the engine restart once it senses you ease off the brake? So, you take your right foot off the brake and apply it to the throttle and you get a lurch?
I think it is basically as you ease off the brake and the engine restarts, the next part where the transmission re engages is the tricky part. It has usually jolted before the accelerator has been touched. So yeah you can do a slow ease off the brake to try and control it to an extent.
If i do it with auto hold it is trickier as the engine is re started by the accelerator. I haven't thought of a method to smooth that way out.

The Bone Ranger
19-11-2014, 09:05 AM
If i do it with auto hold it is trickier as the engine is re started by the accelerator. I haven't thought of a method to smooth that way out.
If you give the brake pedal a good prod, it will start the engine once again. This is useful if you know the traffic lights are about to change in your favour, or you can see a gap opening in the traffic. it doesn't sort the co-ordination issue conpletely, but is useful if you want to avoid any issues in tricky traffic conditions.

For me, most of what everyone has said were all issues in the early days of ownership, but my technique has improved to the point where it is a non-issue.

Andrew

Hillbilly
19-11-2014, 09:18 AM
Easiest way is not being lazy and turn off Auto Hold As it defeats stop start on my car I never use it.

But then its flat around here so dont really need it.

Easier just to keep foot on brake and then ease it off to let engine start as lights change and then it pulls away normally.

Maybe the mk7 is different in operation as if I hold the brake on hard the engine stays off Have to lift foot for it to restart

BCK
19-11-2014, 04:28 PM
Should the engine restart once it senses you ease off the brake? So, you take your right foot off the brake and apply it to the throttle and you get a lurch?

Foot off brake

car starts

foot transitions to throttle - no clutches engaging

foot depresses accelerator pedal 5-10%

clutches still not engaging for a few seconds (this is a hint its about to happen - as usually it'll start engaging the clutchs into a "creep" mode after a second.

Clutches engage violently and throw the car forward - no change in throttle input - car then continues moving relative to initial throttle input.

So its not like the ecu is picking up a quick and large accelerator input and trying to get away in a hurry, it just lurches, and then slowly crawls away at the speed id expect in relation to the throttle input i have given.

The next few times it does it (start/stop activation), its flawless! And moves away from rest gently, just fine.

But then again, out of nowhere, itll bite the clutches hard and spear me forward with startling force once again.

BCK
19-11-2014, 04:34 PM
Easier just to keep foot on brake and then ease it off to let engine start as lights change and then it pulls away normally.

Maybe the mk7 is different in operation as if I hold the brake on hard the engine stays off Have to lift foot for it to restart

Nope. If your foot is on the brake and you lift it a small amount, my MK7 restarts.

But you dont need to lift off all the way for this to happen.

Hillbilly
19-11-2014, 05:23 PM
Nope. If your foot is on the brake and you lift it a small amount, my MK7 restarts.

But you dont need to lift off all the way for this to happen.

Thats exactly what mine does so to get off the mark this is what I do.

If at the lights, watch them,

Lift foot slightly off the brake,,
Engine starts, wait for lights..
Lift foot off brake pedal, wait the few milliseconds for car to start to roll,
Hit the loud pedal as required. Gently for a start, Get it rolling and then hit it up a bit.

Same for in traffic, but never let it sit on the clutches as you would in a slush box.

BCK
19-11-2014, 07:37 PM
Yeah, that's what i try to do but a lot of the roads im on are 2-way, or simple stop-start traffic - so i dont have the luxury of traffic foresight.

Most of the time i cant preempt what triaffic is doing ahead, therefore i wait for traffic to properly get moving before coming off the brake. Otherwise you're essentially riding clutches.

Hillbilly
19-11-2014, 07:53 PM
Yeah, that's what i try to do but a lot of the roads im on are 2-way, or simple stop-start traffic - so i dont have the luxury of traffic foresight.

Most of the time i cant preempt what triaffic is doing ahead, therefore i wait for traffic to properly get moving before coming off the brake. Otherwise you're essentially riding clutches. If you lift off the brake far enough to start the engine but keep the car still I dont think the clutches engage till your foot comes right off

Melts75
19-11-2014, 08:17 PM
My wife and I both are both in the habit of first starting the Passat then reaching for the Auto Stop/Start button shortly after, To turn it off!! It's the most annoying system, and the pissy amount of fuel your going to save is not going to cover the cost of premature wear of the turbo from oil deprivation.
The Auto hold I found useful on my 09 Tiguan manual, but in an Auto?? I think it's been turned off for about two years now!!
Combine the two and try a tight reverse park :-))


2011 B7 Passat TDI highline wagon. I tinted the windows [emoji106][emoji106]

BCK
29-11-2014, 12:19 PM
True, but my issue is creeping with traffic.

Hillbilly
29-11-2014, 12:55 PM
Heres what your problem is.

Unless you put it into 1st manually it sits in 2nd Well does in the Polo anyway The hesitation you are getting is it dropping into 1st when you mash the throttle Just let it roll a bit then apply power gently. Look at your MFD and see what gear its in when you stop.

Neither of mine do what you say.

Driver differences I guess You should never let it creep in traffic as it will burn the clutches

BCK
30-11-2014, 09:57 AM
Mine drops to first in my Golf R-line (7 Speed).

Waiting for it to engage and start creeping after releasing the brake can sometimes cause a looooooong pause before it actually engages anything.

On quiet nights, or in a carpark, you can hear the mechatronics working and selecting 1st/2nd. My Golf selects first at a stop and also shows this on the MFD, then at approx 5kph will slip the clutches into second and keep slipping them until road speed speed is sufficient enough to allow complete engagement of 2nd gear above 1,200rpm or so.

So while your theory may apply to your Polo, the Golf obviously operates differently.

Besides, if you read some previous responses (mine being one of them), you would see that mashing the throttle is not what we are doing. The main cause is the stop-start and the following transition off of brake to throttle. Not lightning quick jumps from one to the other.

dening
30-11-2014, 11:15 AM
Heres what your problem is.

Unless you put it into 1st manually it sits in 2nd Well does in the Polo anyway The hesitation you are getting is it dropping into 1st when you mash the throttle Just let it roll a bit then apply power gently. Look at your MFD and see what gear its in when you stop.

Neither of mine do what you say.

Driver differences I guess You should never let it creep in traffic as it will burn the clutches
My 6r gti Polo was way different to my current golf gti. It's not really something with technique.

I have a loaned tiguan at the moment from vw (brand new highline diesel) and it doesn't behave like the gti. Even with stop start it doesn't jump if you slightly hurry it like the golf does.

lambertia
12-01-2015, 08:37 PM
Had my car in for service today and mentioned the issue. The fellow said he has complained about the same thing in his mk7. This is a known issue and there is not currently a fix.

zardoz
21-01-2015, 10:21 AM
I see this with stop start irrespective of whether ACC is activated. 103TSI highline. I find that if I hit the accelerator more fiercely when starting again, I'll get a very sudden jump on takeoff.

GolfVII
28-02-2015, 08:01 PM
Found this
stemei.de .VCDS Codierungen .Codierungsservice .Webdesign - Stefan Meier - Anfahrassistent - VCDS Codierungen, Webdesign (http://www.stemei.de/pages/coding/vw-golf-7/anfahrassistent.php)

You will need to translate it.

Quote:
In the control unit of the electronic brake system gives you the option of the VW Golf 7 and verbautem automatic transmission (S-Tronic) adapt the dynamic start-off. The approach can thus be changed accordingly. Since when shipped to the dynamic start assist with the setting normally relatively late releases the brake is always a strong jerk felt, which causes an overall poor starting performance of the vehicle. If you change the setting to keep the early (and hence the brake intervention) of the Start-minimized and thus you feel no annoying and can hold more - as it should - start smoothly.

mike90tsi
28-02-2015, 10:01 PM
My trip into work is 7.7Km long, I have a Golf Mk7 90TSI base, I use the start/stop and in the hilly bits I turn on the auto hold, in the mornings I get between 43 and 55 start/stop events on the way to work (yep, I counted for a week). Never once have I had what the OP is describing.

skong
01-03-2015, 07:38 PM
Mk7 103Tsi - I had on occasion felt the car jerk as described. Now I give it a few seconds for the engine to come close to idle after each start/stop event before easing on the accelerator. No more jerking; but it does take a little patience. It seems to me from what I have read here that some of the cars here takes longer than others engage the drive train.

MelbMan
02-03-2015, 05:20 AM
Yes my wife's 90 TSI DSG spends very little time in 1 when you take off, a split second and it's in 2. With the stop start we generally turn this off. It's novel the silence in traffic. But might reserve that silence for the day we get a hybrid Golf. The whirr of the starter motor while not loud (BMWs etc are the same) is a bit mechanical for my taste.

lambertia
06-03-2015, 09:08 PM
Mk7 103Tsi - I had on occasion felt the car jerk as described. Now I give it a few seconds for the engine to come close to idle after each start/stop event before easing on the accelerator. No more jerking; but it does take a little patience. It seems to me from what I have read here that some of the cars here takes longer than others engage the drive train.
I've been wondering recently if it's not an issue with a drive train but instead an issue with the auto hold releasing the brake. I often get a delay with the release. I could imagine that if the car is in gear and fighting the brakes that the sudden jerk would occur when the brakes release.

Kesh
08-03-2015, 11:03 AM
I've been wondering recently if it's not an issue with a drive train but instead an issue with the auto hold releasing the brake. I often get a delay with the release. I could imagine that if the car is in gear and fighting the brakes that the sudden jerk would occur when the brakes release.

That's what I believe it is. It's because when the engine starts, the RPM's rise higher than normal, so it might want to settle down first before taking off etc. I find if you don't modulate the accelerator at all when you take off, it's always smooth. Naturally you'll find that you press softer then harder, or harder than softer. Once the lights go green, if you push the accelerator and keep it at that position until the clutch is fully engaged, there shouldn't be any issue. As with the DSG, it does take practice!

agentthumb
04-08-2015, 01:51 PM
Started noticing this with the TSI.

It never happens when the engine is switched off by Auto Stop Start. Happens when I come to a stop by applying minimal brake pressure leaving the engine running (Auto stop start doesn't stop the engine in this case). Auto-Hold is holding the car after this.

When I gently accelerate off the line in slow moving traffic, the rev goes up slightly from idle to about 1100rpm, but then suddenly shoot up to 1200 - 1300 rpm when the brake is released by Auto-Hold, lurching the whole car forward. Again, this doesn't happen every time, just some times.

Is anyone else still experiencing this? Any solutions?

Jimi
04-08-2015, 03:22 PM
I believe the auto hold grips harder the harder you apply the brake when you come to a stop (I think it maintains your braking pressure when the car stops). I now subconsciously reduce pressure on the brake to almost nothing just before the car completely stops, meaning the auto hold is engaged but only very lightly, meaning less jerk when I move away

agentthumb
04-08-2015, 03:29 PM
I believe the auto hold grips harder the harder you apply the brake when you come to a stop (I think it maintains your braking pressure when the car stops). I now subconsciously reduce pressure on the brake to almost nothing just before the car completely stops, meaning the auto hold is engaged but only very lightly, meaning less jerk when I move away

Hmm, interesting. I'll have to experiment with this a bit. Perhaps this is why it only happens sometime, and not others.

agentthumb
26-11-2015, 12:18 PM
So, been driving around with A/C on as it's been fairly hot in Brisbane 30+ degrees. Noticed that this "slap in the head" issue disappears when the A/C is on 100% of the time. But when you turn the AC off, it comes back.

I have been driving with Stop Start and Auto Hold ON. With AC on, no issues. Turn AC off, jerky take off ensue. Bit strange...


Just to clarify, I have observed under these conditions (Auto hold and Stop Start on all the time):

AC On:

Engine stop -> take off = Fine.

Engine running -> take off = Fine.



AC Off:

Engine stop -> take off = Fine.

Engine running -> take off = Jerky start 80% of the time (but fine when the car is either pointed up or down hill)



PS. Has anyone tried changing the AUTO-HOLD setting via VCDS (03 ABS Brakes -> 10 Adaptation -> Hill Start Assistance) to address this issue? If so, care to share your findings?

agentthumb
05-01-2016, 02:49 PM
Just an update on this issue, changing auto hold to release early has made a noticeable difference. The car takes off much smoother now.

Have tested hill start on some fairly steep hills, doesn't appear to have changed the behaviour of the car in that regard :)


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