I have the 2008 C300 4Matic Sport and I have been noticing transmission jerkiness while easing off the accelerator and in congested traffic and such. I have read that there are issues with the 722.9 transmission, but how do I tell if that is what my car has?

What are the steps to get it fixed and can it be done for free? According to what I have read the TCU just needs a software update.

Thanks.

It sounds like engine braking, which helps you slow down by downshifting. You can reset your TCU because it learns your driving style.

-Turn your car to the ON position
-Press the gas pedal all the way down and hold for 5 seconds
-Turn your car off while your foot is still on the gas, but leave the key in
-Take your foot off the gas pedal and wait 2 minutes before turning on your car or removing the key

You'll need to do this every few days because the TCU will learn your driving style.

I actually did stumble across this. I tried it already, but I wasn't going anywhere so I had my door opened and this probably stopped it from working. It was saying to take keys out or turn lights off once I turned my car off and took my foot off the gas.

From what I heard, I probably need to shut the door and turn everything off like radio, air, lights, etc. and then do those steps and sit in the car quietly for 2 minutes without opening the door.

I'll try it out tomorrow before work and if that doesn't work I'm thinking about getting my TCU software updated.

Also, is your car in sport mode? Maybe it downshifts to 1st gear, which is probably the most noticeable shift you'll feel.

I have noticed it in both modes. It feels pretty darn chunky not gonna lie.

This really seemed to have worked! Highly recommended for anybody that has the same issue or bought a used mercedes.

I have noticed this also but mostly when slowing down to a T junction at the top of a hill. Mine is probably the down shift by the sounds of it, which makes sense.

Has anyone tried this method to reset the TCU on a UK vehicle?