Body Control Systems

The majority of cars manufactured since early 2000 and for some manufacturers such as BMW, Mercedes and VW for example many years earlier, have had 1 or more Body Control ECU's that perform all sorts of functions in modern cars.

Gone are the days when you push a switch to open the window that completes an electrical circuit to open or close a window for example, these days it is much more likely that pushing a switch sends a signal through the cars Can Bus network to the body control ecu that then sends a signal to the window control motor telling it to open or close the window.

Although this is a very simple example, the point behind this is that it allows such things as automatic window closure when you lock or alarm the car.

The problem is that while all this extra functionality may seem like a good idea when everything is new, as soon as moisture and condensation get into the systems it does not take much to cause all manner of problems

VW Passat Body Controller Problems

The VW Passat is a good example of one of the many models of car that suffer with body control system problems.

Many owners are not aware that when the interior light starts playing up they are at the start of what can be a very expensive repair process if not caught and rectified before the damage goes to far.

So first the interior light plays up, then problems with the central locking and windows, windscreen wipers at the front and rear of the car, boot locks not working, all of these problems are normally intermittent to begin with, but eventually you have windows that don't work at all and as we have seen on an increasing number of cars doors that lock closed and a re "dead locked" preventing them being opened even by a locksmith.

All of these problems on the Passat are caused by one of the water drain channels becoming blocked in the engine bay, if not cleared this results in the water running into the passenger side floor pan and corroding and even shoring out the body control ecu that is sited under the carpet. Unfortunately due to the extensive insulation and air space under the carpet the carpet itself can seem completely dry, so the problem goes unnoticed until it has already started to cause problems.

We regularly repair the results of this kind of damage on a wide range or manufacturers and models of car.