Old problem finally fixed.

For a long time my DSC warning would come on anytime the ambient temperature was above 70f. I had already checked wheel speed sensors, had steering angle sensor reset and nothing would cure the problem. Yesterday, an older man backed into my back bumper in his Mercedes. No damage was done other than one side clip coming undone. I reattached the bumper to the clip and promptly forgot about it. Went to get into the car this morning, and the car would not unlock either by using remote or by turning key in the doorway lock. Mine is a touring, so there is no rear keyway. I pulled on the door handle in desperation and voila. The remote worked. I started checking things and finally found the ground to be loose (nut loose) behind driver side trunk cover. Everything works correctly, plus no more DSC alarm. Check all those grounds when chasing electrical gremlins.