Headunit-Basic: CID is blank and "NO SIGNAL" is Displayed. Intermittently the Central Information Display (CID) is blank and "NO SIGNAL" is displayed on the CID. ??Fault Code B7F8C3 "no response from CID (HW error: loss of CID communication)" is stored in the HU-B Error in the Headunit-Basic (HU-B), also called Radio Professional or ENTRY head unit.