When I park at home, I'll put the car in Park and flick on the parking brakes. Next morning when I start the car, push off the parking brakes, foot on brakes and switch gears from P to D, the car would "jerk" down/forward. It seems like this "jerk" motion is more 'violent' the longer I've parked my car.

I'm not sure if this is a problem with the electric parking breaks or...? Has anyone got any idea?

My F-type is an S, brand new (MY2015) and I've noticed this problem when I got the car a few weeks ago. I've driven a few hundred miles now and the car's due for a maintenance but I want to know more about this issue before the talking to the mechanics.

Any ideas?

 

I think it's just a symptom of releasing the EPB.
I don't apply the EPB when parked up overnight in my garage, as it's flat and level, and I have no such "jerk".
But when I park overnight at SWMBO's joint, I do apply the EPB coz it's a quite steep driveway, and I notice a slight jerk when I first put the car in R.
Also, when taking a rear wheel off with the EPB on, when I drop the car back down again the suspension sits way high until I release the EPB, and then it drops back to normal height with a loud creak.

 

Ok, so you think it's the EPB. That's what it felt like to me too.

If having the EPB on for longer accentuates the jerking motion, would that be normal too? If I have the EPB on for an hour or two and then start the car, there's almost no jerk.


In the beginning I thought it could be a problem with tranmission fluids because I do feel a small jerk some other time, i.e. when decelerating on AT when approaching a red light...I think a small jerk is present when it shifts from AT gear 2 to gear 1.

Edit: Grammar

 

Ok so i found a related topic.
https://www.jaguarforums.com/forum/f...-153622/page4/

 

Mine does that the first time I put it in D after sitting overnight...just once though.

 

I just recently had this issue resolved by the dealership with a TCM flash.

I had to push the dealership hard on this, I was told over and over again that it is normal and not to be concerned. After several trips and a test drive with the shop foreman, they ran a diagnostic and determined that there was a newer TCM software version (I have a 2015).

I had provided the TSB mentioned in the other thread prior as well, but apparently that TSB is no longer in the system. I had to be a persistent PITA to get this done, but not only is the jerking gone, shifts are noticeably smoother as well. Well worth the effort.

 

I have an MY 2015, first time registered April 2014. I bought it second hand in June 2015, and when I asked the service dept if it had been in for any works/updates, I was told that it had had a software update on the automatic transmission system.

The first owner of the car was one of the top managers in Jaguar Germany.

I have never experienced any kind of jerking when I start it up and set it in D or R - no matter how long it has been parked.

 

The V6 XE does the exact same thing. If I let the engine and cats warm up beforehand (until the RPMs drop to normal idle), it does not jerk at all.

 

I'm bringing the car to a Jag workshop this week so I'll ask about the TCM flash

It's just weird because I always felt that forward jerk was something more mechanical. I'm not sure how a software update could fix this but let's hope it does!

 

Engine speed and valve settings within the transmission can be adjusted by the computer. That and other parameters will affect smoothness of the shifter transition.