From Ross-Tech Wiki

00857 - CD Changer Unit (R41)

00857 - CD Changer Unit (R41): No Signal/Communication

Possible Symptoms

  • CD Changer Unit (R41) not working

Possible Causes

  • Wiring/Connectors from/to CD Changer Unit (R41) faulty
  • CD Changer Unit (R41) not connected
  • Control Module Coding incorrect

Possible Solutions

  • Check Wiring/Connectors from/to CD Changer Unit (R41)
  • Check Control Module Coding

Special Notes

  • Some factory installed Features like iPod interfaces use the same CD-Changer input on the radio.
  • 3rd party or non-standard units which connect to the CD changer interface may cause such fault codes, so unless you are experiencing real problems just ignore this code.