If this affects you, chances are that you've already received a letter in the mail from General Motors and OnStar informing you that the analog network supporting older GM models with the OnStar service will be turned off on January 1st, 2008. The reason is because the Federal Communications Commission ruled in 2002 that cellular companies could stop supporting their analog networks in favor of digital ones, and OnStar was originally set up on an analog network owned by Verizon Wireless in 1996.
GM began selling vehicles with dual-mode (analog/digital) hardware in 2004 after all appeals to the FCC to overturn its ruling had failed. All GM cars and trucks are now likely sold with digital-only equipment. Some GM vehicles produced between 2002 and 2004 may have been equipped with analog hardware that is digital ready, meaning it can be upgraded to accept a digital signal. To find out if your vehicle is digital-ready, click here and have your VIN ready. If you do have equipment that can be upgraded, GM will do it for you, including parts and labor, for only $15 if you agree to a $199 1-year subscription to OnStar.
Nevertheless, it's a bum-deal for those GM customers with older OnStar models that can't be upgraded, as their service will ride off into the sunset on New Year's Eve thanks to the FCC.
[Source: Straightline, GM]