I have a Mercedes w221 58 reg and yesterday my rear air suspension gave up on me. I called out the AA who advised the sensor bracket had rusted and could only locate half. He adjusted my suspension to high and then followed me home. I checked the forums and managed to locate the part for £20.00 from main dealer and proceeded in my car to Halfords. They struggled to put the sensor on due to little space to move. But on taking the car off the ramp the car still was high so he went on his machine and slowly very slowly the suspension adjusted to ultra low rider mode at the rear then the above message appeared. They huffed and puffed tried re diagnostic removing any daul codes then it went in to test drive mode what ever that is but then said sorry mate main dealer reset. I called the AA and advised what happened and was directed to a Mercedes specialist who advised that as the abs light was on as well the and sensor was damaged causing the issues as the car is not apparently in workshop mode. The part has been replaced and I can drive the car even if the rear is like a lie rider. Can any one suggest how I can reset the mode I have started the engine moved steering to right all the way and left many times but messages stays on. Help as I don't want to pay £££££ for a fault that was not mine as there were no lights on before I took it to HalfordsI appreciate the length of this post is long but I thought I would list the whole scenario Thank you in advance