Brake light on and in limp mode

Hi, my name is Devin. I am an auto repair expert with the Car Genius team here at RepairPal. I'm sorry to hear you're having trouble with your vehicle. It sounds like there might be a sensor issue related to the recent work done on the steering knuckles of your ML320. The brake light being on and the vehicle going into limp mode could indicate that something in the ABS or wheel speed sensor system is out of place or damaged. When these sensors aren't working correctly, the vehicle's safety systems can engage limp mode to protect the drivetrain. Rechecking the connections to the ABS sensors and ensuring nothing is loose or unplugged would be an excellent first step. Performing a diagnostic scan may also help to point you in the right direction. If you need more advice, have any other questions about your vehicle, or would like to get connected to a RepairPal Certified shop near you, we have you covered. Give us a call at 877-913-1554, and we will happily help you out!