I've got a 2007 Passat TDI with the DSG gearbox (which is Ok most of time, a bit jerky in traffic but its only my second auto so I've got little to compare against)
One thing I've been playing with is the Auto Hold function, where the car 'locks' when stationery as if you were holding the brakes.
Does anyone know how this works? is it actually applying the brakes, or is it holding the car on the clutch somehow? It doesn't seem to use the handbrake (its the electronic thingy on mine) as you can hear that engage/disengage when you use it.
Just curious really, as this DSG gearbox seems too clever for its own good.
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I had a Passat CC manual which also has auto-hold. It must be using the brakes because once you stopped and let go of the brakes it would not roll forward or back. It cannot have used the clutch because it did it when not in gear.
It will be using the same way of holding the car as the electronic parking brake does.
The DSG is not an automatic gearbox like a torque converter. It has two clutches and select the next gear (up or down) ready for the next (automated or manual) change. Changing down the car also blips the throttle. You should not keep the car in gear and hold it on the foot brake for long periods because it will be slipping the clutch which long term cannot do it any good.
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You should not keep the car
>> in gear and hold it on the foot brake for long periods because it will
>> be slipping the clutch which long term cannot do it any good.
>>
"Handbrake on, gear lever to neutral" should be the procedure in all cars when stopped. Manual or automatic or inbetween.
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>> "Handbrake on, gear lever to neutral" should be the procedure in all cars when stopped.
>> Manual or automatic or inbetween.
The operative word is should. At times in a forest of brake lights and creeping cars I feel as if I'm the only one who does this.
Odd thing is, I've always considered that handbrake on etc, I can have a little rest.
Last edited by: Slidingpillar on Thu 7 Apr 11 at 13:46
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>> "Handbrake on, gear lever to neutral" should be the procedure in all cars when stopped. Manual or automatic or inbetween.
My autobox drops itself into neutral after the brake lights have been on for a couple of seconds. Vauxhall handbook claims its to help save fuel.
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>> a bit jerky in traffic
Is it ok? They should be imperceptibly smooth. There were a high number of "mechatronic unit" failures from around this time (2007) and that can manifest itself as jerky changes at the beginning.
Might be worth having the dealer look at the car anyway, a procedure they'll do as a matter of course is the DSG adaptation procedure. This is just plugging the car into the dealer VAS tool (VCDS will do it too) and the gearbox re-learns correct change pressures for the clutch plates (to account for wear etc). It's done at the DSG oil change time also.
>> is it actually applying the brakes
It does work via all 4 brakes, It doesn't apply any braking pressure though, it uses the pressure you applied and stops the immediate release of the pressure when you release the brake pedal. Pressure is released progressively over the next ~2 seconds.
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I had a 58 DSG 2.0TDi Passat. The box was awfull but at 35000 miles VW finally had a re-call for a mod to the Auto and it was better. They are not as good in refinement as some auto boxes. I found the DSG box was worst when it came to reversing ! it wouldnt creep so you had to use rev's to reverse, so in a small parking space I always thought a bit hairy!
I seem to remember the handbrake calipers used to come on everytime it stopped and released as soon as you touched the throttle. You could alway hear that whine from the rear.
Great car though, I had 3 Passats, all 2.0TDI's and for high mileage were great and fuel economey was fantastic, infact my Hi-line DSG was the best of all 3 and 60 mpg on a long motorway trip was usuall
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Doesn't holding the brakes on warp the front discs due to uneven cooling where the pads are in contact with them?
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I think that's a theory that has no place these days. Looking at the construction of modern ventilated disks, the thickness and the vanes inside the two sides of the disk, I find it hard to accept that a brake pad can dissipate enough heat to make an area constructed like that, warp.
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Agree. Even if the brakes were really hot, I don't think holding them on the pads would cause vented discs to warp - and a sensible driver is unlikely to do that anyway. I don't know what does warp discs, though, because it can still happen (my brother's E270 had a few discs warp)
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Might deposit pad material on the hot discs. Could easily be mistaken for warped discs.
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As far as I know, the problem of warping discs by holding brakes was in extreme conditions, ie a race or having just come down a mountain. One does not hear so much about it these days, presumably due to the cooler running of vented discs.
So probably no longer an issue on a modern car, assuming it is driven normally.
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Volkswagen Passat - VW DSG - Auto Hold - how does that work? - rtj70
