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Discussion Starter · #1 ·
Has anyone else had this problem.

Every once in a while on an uphill grade (not using the "Hold" feature), when I take my foot off the brake, the car starts to roll back, very much like a manual transmission. I hit the gas and there is a delay in the clutches engaging and it's a bit frightening. Often I hit the brake to stop rolling back and then hit the gas again.

It's not often but scary when it occurs. Is this normal or should I take the car in for service?
 

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From my Porsche PDK experience, that is normal. When stopped, the DCT declutches. When rolling back the transmission is bound to falter a bit as it tries to smoothly switch directions. Just like if you were driving a manual transmission ... it is best to avoid situations like this. There is a reason the brake hold feature is there.
 

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Brake hold is a godsend! :)
 

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Brake hold is a godsend! :)
Amen. I first realized it when I was trying to leave a parking spot on a steep hill. Thank the heavens for the brake hold feature, or my rims may have never forgiven me. Lol
 

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Amen. I first realized it when I was trying to leave a parking spot on a steep hill. Thank the heavens for the brake hold feature, or my rims may have never forgiven me. Lol
I find that the brake hold feature helps tremendously when reversing out of a lot that is on an incline. Prevents the car from rolling back and hitting another car whilst changing gear from reverse to drive and stepping on the accelerator. :)
 

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Discussion Starter · #7 ·
Thanks for the info. One clarification. This does not happen when switching from Reverse to Drive. This is happening when I'm in drive, stoping on an incline and then continuing to move forward.
 
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Thanks for the info. One clarification. This does not happen when switching from Reverse to Drive. This is happening when I'm in drive, stoping on an incline and then continuing to move forward.
Yes, this happens quite regularly for me. Especially when I am at an underground carpark and am on an incline waiting for my turn to drive out. When I don't use the HOLD function, my car will slowly creep backwards, when I lift off the brake. I would just feather the accelerator pedal to stop that from happening or engage the HOLD function by pressing down on the brake hard to activate the HOLD function.

I guess it is normal.
 

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I've experienced the very same thing. It's noticeable al low speed in Comfort Mode when in Drive and transitioning from decelerating (foot off the gas peddle) to gradual reapplication of the accelerator. It feels like there's too much Backlash in the Final Drive or the Transfer Case. It's very a curious sensation. You may also notice a lack of responsiveness from the transmission when driving off from stop in Comfort Mode. Very curious indeed whether cold or in normal operating temperatures. In the other Drive Modes, the responsiveness returns and I've noticed this situation when driving in other car of the same model. Mine is a 2018 GLA45. This discussion is the only one I've found regarding this phenomenon on the internet.
 

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I've experienced the very same thing. It's noticeable al low speed in Comfort Mode when in Drive and transitioning from decelerating (foot off the gas peddle) to gradual reapplication of the accelerator. It feels like there's too much Backlash in the Final Drive or the Transfer Case. It's very a curious sensation. You may also notice a lack of responsiveness from the transmission when driving off from stop in Comfort Mode. Very curious indeed whether cold or in normal operating temperatures. In the other Drive Modes, the responsiveness returns and I've noticed this situation when driving in other car of the same model. Mine is a 2018 GLA45. This discussion is the only one I've found regarding this phenomenon on the internet.
During the fluid change of the rear differential last Sunday I looked for the "play" in the drive line and witnessed it prominently between the drive shaft and the input to the differential. So it's obvious that the design is purposeful, but seems very odd to me for the stress it must impose on the differential when under hard acceleration. Seems an unusual design. Anyone know why?
 
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