Topic: Active brake assist is off, cruise don't work  (Read 438 times) previous topic - next topic

Says to clean sensors. Where are they on 2019/20 unity TB

We just ran into this a few times in the last few days.  I would try to clean the windshield in front of the rearview mirror first, that did it for us once (big bug splats).  The camera and/or radar are behind there as far as I know.  It did it two more times and it was after being on fairly traffic free roads for a long time.  I did some searching and found that some folks believed it to be because if it didn’t see the back of a car for a while, it must not be working right and shuts itself off.  I have no idea if that’s true, but the advice I found was to follow close enough behind another vehicle that the van “sees” it and will restart after a period of time.  Sounded a bit wonky but I did it and it worked both times.  So, follow someone for a bit and see if it restarts, worked for us!

On a Mercedes-Benz Sprinter, the sensors for the Active Brake Assist system (also known as Active Distance Assist DISTRONIC or Collision Prevention Assist) are primarily located in the following areas:

Front Grille: There is a radar sensor behind the Mercedes emblem or grille, which is responsible for detecting objects and vehicles in front of the van. This sensor is essential for the system to calculate distances and recognize potential collision threats.

Windshield (behind the rearview mirror): A camera mounted near or behind the rearview mirror monitors lane markings, vehicles, and other objects in the van's path. If this camera gets dirty or obstructed (e.g., by dust, snow, or ice), it can affect the system's functionality.

To clean these sensors:

For the radar sensor, gently clean the grille area with a soft, damp cloth to remove any dirt, bugs, or debris.
For the windshield camera, ensure the area in front of the camera is clean. Avoid using abrasive materials that might scratch the windshield in that section.
Once the sensors are clean, the system should resume working as intended. If the warning persists, you may need to have the sensors recalibrated by a dealer or certified technician.