I just finished replacing all 4 control arms, first time getting my hands dirty with a MBZ. My goal is to get the car back in top shape to install the Eurocharged 185 pulley and software combo.
Well finished the job, went for a drive and the car drives very well, I now need to take to a shop to do the alignment. Now I notice after the first test drive the following message "ESP not available, visit workshop!". I didn't disconnect any of the wheel sensors so Im puzzle as to what it could be. Any ideas? maybe the wheel sensor went bad while replacing the control arms?
Also when I put the key back in the malfunction is not there, it shows up within seconds of starting the car

My guess is that you probably damaged either the left or right speed sensor. I had the same issue when I did my suspension. I replaced both since they are relatively inexpensive.

Alignment fixed it

sometimes turning the wheel all the way to the left then to the right fixes it..
did you replace tie rods too? am in the process of doing the same job..

I tried going left and right full lock and didnt do anything. The alignment fixed it. I did the hole front suspension, car feels much tighter now.

I'm curious as to how the car knows that the alignment is off. I can't think of any sensor that your know that.

Aughh i replaced all control arms and have the esp error as well. But it took 30 minutes of driving to trigger it. My alignment seems way off though as my steering wheel is pointed about 15 degrees to right to go straight. I am guessing wheels are fighting each other and spinning at different speeds causing the alignment to be messed up? I did not think the difference would be that much but i dont know how sensitive this whole system is.

Was your steering wheel pointing straight ahead after you repaired your suspension? after wheel alignment it most likely pointed straight again.
ESP has a steering angle sensor. the control unit has a zero point offset which allows for a few degrees tolernace of wheel offset, after your repair the Yaw sensor showed no yaw accelleration yet the steering angle is reporting a turning angle of a few degrees due to your repair.. So it puts the light on. after your alignment, your steering angle input and yaw rate "agree" so the light goes out.