Vehicle rolling forward in reverse

[wavesalon]

My 1 week old 90TSI comfortline has had two occasions with behaviour that was very scary. What does everyone think about this:

Car stopped in a parking space, engine still running, in park gear, electronic hand break engaged. Then brake pressed on, gear engaged to reverse, handbreak released, and break slowly released. Then the scary thing happened. The car instead of going backwards ( as you would expect with a reverse gear), it actually started rolling forward. It felt like the kind of free rolling down the slope, as the ground was indeed sloped forward. So i immediately pressed on the breaks to stop it. The second scary thing happened : breaks were completely unresponsive !

I had to quickly put the gear to Parking and stop the car moving further ! happened everytime i tried the same maneuver, until i restarted the engine.

Can anyone help me? whats wrong? is it my fault with not setting up the car properly or does it sound like its a DSG or software glitch.

i feel very scared using this car now. can't imagine what would happen if this occurred at cruising speed.

[Transporter]

What did the dealer say when you reported the fault to them?

If you didn't, then it's hard to advise something, might as well be a driver error. I expect any automated transmission to have a bit of roll on the steep slope.

Didn't you already posted your problem? Here? http://www.vwwatercooled.com/forums/...ml#post1006124

I did modified your post and linked it to this thread, so we don't confuse the Golf7 owners that there are already 2 cars with this problem.

[Nauend]

I've experienced something partially along these lines, but mine seems to be due to a delay between auto stop/start starting the engine and the auto brakes being released, where the brake is released when you press the accelerator but the engine does not start immediately as it just stopped the engine so the car rolls. Seems like the dsg clutch is not engaged until the motor kicks over.

Good example of when this happened is a queue to get through a carpark boom gate when auto start/stop is on. the car does not react quickly enough. Simple solution is to turn auto stop/start off(which I do now when a boom gate is involved!), but I don't think that's a long term solution given you can't turn it off permanently.

I'm booking mine in for a couple of issues (leaking rear window washer, and random auto brake not being auto) but might see if I can (safely) replicate what happens in my car before I drop it off.

[Guest001]

With all those "breaks" it must be broken LOL If you don't apply the foot BRAKE really hard the motor wont stop and it then wont roll away when you take your foot off as the clutches will engage faster.

I find I can roll up to the lights and hold the car steady without the motor turning off if I want to Only do it when I know the lights will change fairly quickly.
Don't really recommend it though as not sure if the clutches fully disengage or not.

[AdamD]

I've updated the title of this thread to something more meaningful.

The car... actually started rolling forward. It felt like the kind of free rolling down the slope, as the ground was indeed sloped forward. So i immediately pressed on the breaks to stop it. The second scary thing happened : breaks were completely unresponsive !

When you say the brakes were "completely unresponsive", what do you mean? Did they require extra effort to slow the car? If you put the DSG into Park while the car was moving at any significant speed (without first stopping the car with the footbrake), there would possibly be transmission damage caused. You are referring to the footbrake and not the handbrake, correct?

The brakes themselves are hydraulic and operate entirely independently of the transmission, so what you are suggesting is that the car exhibited brake failure. If the engine was not running (stop/start?), then there may have been insufficient hydraulic pressure with which to provide strong brake assistance, although if the engine has been running then there should still have been enough pressure remaining in the system for one or two hard stabs at the brakes. Can you confirm the engine was running the entire time? Or may it have stopped as part of the stop/start mechanism?

[pologti18t]

Then brake pressed on, gear engaged to reverse, handbreak released, and break slowly released. Then the scary thing happened. The car instead of going backwards ( as you would expect with a reverse gear), it actually started rolling forward. It felt like the kind of free rolling down the slope, as the ground was indeed sloped forward. So i immediately pressed on the breaks to stop it. The second scary thing happened : breaks were completely unresponsive !
.

Did you at anytime press on the accelerator? You just mention releasing the foot brake slowly.

[wai]

I take it you have a DSG. Unfortunately, this is standard operating procedure for a DSG equipped VW.

So, if it is a DSG, basically, the clutch does not start engaging for around 1/2 to 1 second after your foot comes off the brake. During this time, the car will roll forward. If you apply a bit more accelerator, when the clutch does come in, it will launch you backwards, so you jump on the brake and start all over again.

With an old style manual handbrake, you end up having to do a handbrake hill start where you release the handbrake when you feel the clutch bite. With the new electric brake, you are going to have to work out a technique.

Based on the operation of the unit, you might want to find an open space with a slope and practice this.

Car stopped facing downhill with the electric park brake engaged.

With foot on the foot brake, put the transmission in reverse.

When you are ready to reverse up hill, take your foot off the foot brake and apply a little (I mean little) accelerator.

When you "feel" the clutch bite (roughly 1/2 second), release the electric park brake. If you are used to doing handbrake hill starts, it is a little easier.

It will take some time to get the balance right, but once you get used to it, it will become second nature to you.

No point taking it to the dealer as you will be told "it's standard for that type of vehicle".

One point to note is that the VW has "brake throttle override". What this means is that when you apply the brake, the ECU will override the throttle (accelerator) to prevent you trying to drive with the foot brake applied. When I had an alignment check done some weeks ago, I got called to the workshop because the mechanic could not get my Caddy to move. It turned out, he was trying to "ride" the brake to inch it on to the turntable, but as he had not released the foot brake, the clutch had not started to engage!

[yauipop]

I'm not sure of the exact behaviour on a DSG equipped vehicle, but for my 6-speed manual with electronic park brake, it will automatically disengage once the car is in gear and accelerator being applied. Perhaps in this instance it's best not to disengage the park brake before applying the accelerator.

[Guest001]

I take it you have a DSG. Unfortunately, this is standard operating procedure for a DSG equipped VW.

So, if it is a DSG, basically, the clutch does not start engaging for around 1/2 to 1 second after your foot comes off the brake. During this time, the car will roll forward. If you apply a bit more accelerator, when the clutch does come in, it will launch you backwards, so you jump on the brake and start all over again.

With an old style manual handbrake, you end up having to do a handbrake hill start where you release the handbrake when you feel the clutch bite. With the new electric brake, you are going to have to work out a technique.

Based on the operation of the unit, you might want to find an open space with a slope and practice this.

Car stopped facing downhill with the electric park brake engaged.

With foot on the foot brake, put the transmission in reverse.

When you are ready to reverse up hill, take your foot off the foot brake and apply a little (I mean little) accelerator.

When you "feel" the clutch bite (roughly 1/2 second), release the electric park brake. If you are used to doing handbrake hill starts, it is a little easier.

It will take some time to get the balance right, but once you get used to it, it will become second nature to you.

No point taking it to the dealer as you will be told "it's standard for that type of vehicle".

One point to note is that the VW has "brake throttle override". What this means is that when you apply the brake, the ECU will override the throttle (accelerator) to prevent you trying to drive with the foot brake applied. When I had an alignment check done some weeks ago, I got called to the workshop because the mechanic could not get my Caddy to move. It turned out, he was trying to "ride" the brake to inch it on to the turntable, but as he had not released the foot brake, the clutch had not started to engage!

Don't know if the Mk7 is different but my Passat electric handbrake releases automatically as I apply foot to loud pedal. Also using AutoHold keeps it in place until power is applied and then it just takes off. The Brake DOESNT RELEASE if you don't have your seatbelt done up. Has to have the button pushed in that instance

[Mountainman]

Don't know if the Mk7 is different but my Passat electric handbrake releases automatically as I apply foot to loud pedal. Also using AutoHold keeps it in place until power is applied and then it just takes off. The Brake DOESNT RELEASE if you don't have your seatbelt done up. Has to have the button pushed in that instance

My Mk7 manual behaves exactly like this - need to have the door shut, seatbelt on and the park brake releases automatically as the clutch is released. We live and drive where there is a lot of hill starting both forwards and reversing and our Golf has performed faultlessly over the 18,000km of ownership. We always leave the park brake and auto hold on. I've forgotten there is such a thing as a "real" handbrake until I get back into our Forester and then there is the usual readjustment - handbrake off and indicators back to the right (correct?) side.

From what I read here it seems like the more rewarding driver involvement of a manual gearbox also brings the bonus of being a bit more accomplished than the "smart" DSG can manage. What's this 1/2 to 1 second wait about? Don't need it in the manual.

[tonymy01]

The person may have been trying to accelerate with foot on brake pedal? Or pumping the brake pedal with engine off= vacuum assistance gone and requires harder push to brake. Hard to make out exactly what happened for them.

Surely the electric brake is like a hill hold and no need to touch it as once the clutch bites to want to move the car, the electric park brake will disengage.

But not speaking from experience here, just posts about the ebrake.

[wai]

The thing is that if you manually release the electric brake, then you will have nothing holding you.

So, if you have the AutoHold set, then don't manually release it, let it automatically release. Even here, it all depends on when it releases. The clutch will only start engaging between 1/2 and 1 second after a change in accelerator position is detected. If the AutoHold releases immediately, then you can still have issues as there will be a point where the clutch has not engaged, but the brake has been released.

[Guest001]

Would be good if the OP would come back with a reply as to whether they resolved the problem

[Transporter]

Would be good if the OP would come back with a reply as to whether they resolved the problem

Give him a bit more time mate. But, don't be surprise if he will not let us know. Many people joint this forum only to post their negative post and then just forgot about it, especially if the problem was with the driver.

[grtuned]

Hill hold assist and brake assist are two totally different features and should not be confused. Firstly hill hold is controlled by the electric hand brake and is always operational if switched. Second brake assist is controlled by the ABS module this applies brake fluid pressure for a maximum 3 seconds before it's released and car will begin to roll it only works on an incline in D or R but will not work in D if the car is pointing down a hill. The problem with the DSG is it's all to technical for people to understand when all that anyone wants to do is just drive. How confusing has everyone's explanations been do this,do that,stop here,press this and so on. DSG'S are by far the worst gearbox the only thing they do well is change gear quickly when will VW axe these rubbish units and bring back a regular auto so people can just drive???