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Discussion Starter #1
I was wondering is it normal to jerk when moving slowly between 5-15 mph. I've noticed that it will jerk alot when moving in traffic.

I told the dealer but they weren't helpful said they couldn't duplicate the problem. Seems like all they car about is a warning light.

I've also noticed that sometimes my Smarty will start slow. Kinda like when a battery is weak. It's not the battery it's brand new. Please let me know if anyone has those problems. Dealers don't seem to be much help
 

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Heh yeah, none of my dealers will try to fix anything unless there's a CEL.

In fact, when my 451 was brand new an unnamed dealership in Chicago once told me they wouldn't cover my botched-from-the-factory alignment unless it threw a CEL...but uhm, that's uh, pretty impossible?

Anyway, as for your issues, hope these help! :D

1. Is your 453 on the original transmission firmware? I found my 453 to do similar. The dealer updated the firmware and reset the transmission, after which the big jerks went away.

That said, the transmission is still a DCT, so some jerking is normal since it's not a traditional automatic or CVT.

2. The starter in the 453 is different from the 451. If you do not hold the key in the start position until the engine fully starts, it may shudder and hiccup trying to start.

This is different than the 451 because the 451's starter is automated in that doesn't care how long you hold the key in the start position. Why the change? Beats me.. :shrug:
 

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Discussion Starter #3
So I recently took it to the dealer for a warning light that was for a coolant valve shutoff. They checked the tranny and said it was updated and everything.

1. Before I took it in it jerked quite a bit from starting at a red light to slowing down at a light. That seems to be fixed. Not sure why lol.

2. I drove the loaner smart as mine was in shop for a while. And the loaner was the same as mine and it was buttery smooth nearly all the time.

3. I asked them why mine was not smooth like that and never really got a reply. The jerk I feel when in traffic is not comfortable it's kinda violent and annoying. Kinda like when on a roller coaster going up a hill jerky.
 

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So I recently took it to the dealer for a warning light that was for a coolant valve shutoff. They checked the tranny and said it was updated and everything.

1. Before I took it in it jerked quite a bit from starting at a red light to slowing down at a light. That seems to be fixed. Not sure why lol.

2. I drove the loaner smart as mine was in shop for a while. And the loaner was the same as mine and it was buttery smooth nearly all the time.

3. I asked them why mine was not smooth like that and never really got a reply. The jerk I feel when in traffic is not comfortable it's kinda violent and annoying. Kinda like when on a roller coaster going up a hill jerky.
The shift programming may have done the trick. Keep in mind that dual clutch "automatics" are really self-shifting manuals that use one clutch to engage odd gears and another clutch for even gears, and throttle pressure will have an effect on shift smoothness. Some drivers are bothered by some jerkiness, but usually aren't aware that throttle pressure and timing of it can greatly manage (or mismanage) the smoothness.

"Good" (in the opinion of some) shift programming will mean a less sensitive and responsive throttle as the computer overrides some throttle input in favor of working the clutch harder to hide what may come across as jerky shifting behavior. It's a good tradeoff for most drivers, however for those DCT experts out there it means a less precise throttle and slower responses when downshifts or upshifts are called for based on throttle pressure.

Less aggressive downshifts, less likely to downshift with slight throttle pressure, less likely to upshift while slightly backing off the throttle, and more likely to clutch in while in gear while you are creeping at low speeds instead of being in neutral and dumping the car into 1st or 2nd while applying throttle pressure. I don't believe your car had a mechanical problem.

With regards to your engine occasionally turning over slowly, this is a common occurrence for small turbo engines every once in a while.
 
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