i found this on Ross-tech... Could my concert radio be getting in the way?. It mentions k-line one of the problems the computer suggested.. what does it mean?. Concert and Symphony Radios These are made by Matsushita. The Concerts have blatant bugs in the diagnostic protocols. We've added one work-around to the low level protocol drivers that works in some, but not all Concerts, and it is not 100% reliable in any case. Some Concerts occasionally get "stuck" in an undesirable mode after attempting communications. If your Concert gets "stuck", the way to reset it is to remove all power from from the radio for at least 10-15 seconds. This can be done by: Removing the radio from the car. Disconnecting the car's battery Pulling the fuse for the radio. Note: Some radios will require you to enter the "security code" using the radio's front panel after losing power. See the owner's manual for the radio for instructions. It appears that I suspect there is something not quite up to snuff in the Symphony's ability to drive the K-line. We've had some reports that they work better with non-optically isolated interfaces, and they may work better with the engine running (which means there is a higher voltage on the VBatt lines in the car).