Chrysler (FCA US LLC) is recalling certain RAM ProMaster Trailer Light Modules, part number 68229650AB. These accessory modules were sold for installation on RAM ProMaster and ProMaster City vehicles. The Trailer Tow Lighting Control Module may have a software error on the affected vehicles and can prevent illumination of the trailer brake lights during brake actuation. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 108, “Lamps, Reflective Devices, and Assoc. Equipment.”