I took my 2009 ML350 for a 40k mls service A and my service guy suggested a transmission fluid change, per Mercedes recommendations.

I had NO issues before the fluid change!

Now, each morning, after about 5min driving, when I come to a complete stop and accelerate (ironically most of the time when I take a right turn) the car gets up to about 20mph and around 2000rpm it suddenly stops accelerating with the rpm staying steady around 2000rpm.

After about a sec costing, the transmission "kicks in" again and I gain speed.

If I get off the paddle or keep my foot on the accelerate, the symptom doesn't change.

The garage thinks it might be the tires - which are used but still ok - that triggers the traction control. I disagree since the problem was digital and immediately after the fluid change, dry street and at low speed hardly hitting the pedal.

I took it back to them today to have it checked out again.

Any ideas or suggestions what the problem could be? What's the legal take on this, sine they made it worse?

Thanks for your inputs!