what is DAS?I believe both of your cars use the D2B fibre optic system. This system works on a ring principle, by that I mean the ring connects the CD player - Command and telephone. If the ring is broken for any reason, be it physical break or a flat battery, then the ring needs a wake up call. This is done using DAS.
Also if one of the units has a problem. ie Command, CD or Telephone, then this can break the ring.