W205 C Class Auto Box Problem

[Forestier]

My car is a Sep 2014 AMG Plus with 7 speed auto.

Went to reverse out of garage this morning, parking brake off, into R, release foot brake. Car not creeping as normal, (and, yes, I had started the engine).
A bit of throttle and it moved but very slowly.
So, into D, jerked a bit and did creep forward.
Back into R, bit more throttle, jerk & it began to reverse.
Road test shows very jerky changes from 1st to 2nd to 3rd.
(From 2nd to 3rd it was a bit like a slipping clutch in a manual)
Same in Comfort, Sport, Sport +.
Jerks changing down into 2nd & 1st.
Second road test and was the same until I slowed to a stop and pressed footbrake to engage 'Hold' function.
On pulling away, gearbox changes were back to normal. Wtf?
Any ideas?
Beginning to fall out of love with the car as it is only a couple of months ago that I had the locking system failure and this on 10,000 mile 23 month old car!

 

[brucemillar]

I would be suspecting ATF fluid level is low as a first point of suspicion. You need to get a dipstick from ebay or a get a friendly independent to check it.

 

[ernie]

It's still in Warranty, take it back to your dealership. Even if it's short of fluid, there must be a leak somewhere for it to lose drive. Hope you get it fixed OK.

Ernie

 

[def90cars]

It's still in Warranty, take it back to your dealership. Even if it's short of fluid, there must be a leak somewhere for it to lose drive. Hope you get it fixed OK.

Ernie

Agreed.... no need for forum moans, or friends with dipsticks, go back to the dealer and use the warranty.

 

[Forestier]

Me - moan?

Not moaning, just putting the details out there in case others have a similar problem, is that not the idea of the forum, shared experiences?
Also, I am in deepest France for another 6 weeks and the 'local' dealer is not local at all. But, yes, I will go if I have to.
I am not so sure it's loss of fluid as the problem has not returned. As explained, after the 'Hold' function was engaged and then dis-engaged by pressing throttle and moving off, the gearbox worked as normal.
I am guessing some kind of computer glitch, does anyone know how the 'Hold' function stops the car from rolling forward? Is it operating on the autobox or brakes?

 

[ernie]

Hold as in second press of the brake pedal operates on the brakes, but the drive is still engaged.

Ernie

 

[ernie]

As it's still in warranty, take it back to dealership, as stated.

However, I was having some rough changes, mainly 3 to 2 on the over-run and when it was in for it's second service I asked them to check it. They updated the g/b software and it is smoother than ever and most changes, up and down, are now imperceptible. I think the new soft-ware matches the engine revs on the downshifts better now than it did before.

Unfortunate that you are so far from your dealer, but I don't think there is an option but to take it back to them with this problem.

Ernie

 

[Forestier]

Thanks guys.