Thanks for the response guys. Matt im using a snap on modis , Darren i have scoped the k bus at the instrument cluster and other modules on the k bus just a straight constant voltage of around 5v if i disconect the general control module behind the glove box this drops to 3.3v and if i disconect the instrument cluster this drops to 0v,
I will try and upload a capture today to show you thanks for the capture this confirms what i found on wds bmw site so i definitly have a problem.
Do you know which module supplies the voltage for the k bus from what i have read i think the general control module is the master for the k bus and the instrument cluster is a stand by controller do one of these supply the votage so the k bus can be active and ready to support messages. www.e38.org/bussystem.pdf (this is where i got this info)