No voltage on fuse 19 CONT

Small, quibbling addendum for the sake of completeness. An OBD scanner will not connect to the CAN; instead, the Gateway interprets CAN data for the OBD port.

The CAN itself is an intensely noisy place: a controller-area network is one in which each node (for example, your TPMS module, your airbag module, various switches, the speedometer) is transmitting/receiving constantly. It is like an open conference call with 200 people, all talking essentially simultaneously, and also simultaneously listening for information that is important to them. They don't so much talk to one another as just yammer down the bus in an unending stream.

One can "listen in" on the CANbus pretty easily: just connect at any point on the network with something (like a modern oscilloscope) that can parse CAN data packets, and watch the data scroll across the screen.

But unless you know the numeric identifier of the specific node you want to listen to, and filter just for that, within moments you will have far more data than you can easily deal with! That said, if you have the right tools, it is a great way to see what is happening on your system in real time and very granular detail.

OBD is far more practical to use as a system monitor, though, because it filters all the data down to useful outputs, e.g. tyre pressure, inlet air temperature, etc. CANbus "sniffing" is more for really in-depth troubleshooting of specific electronic modules. Or, for advanced players, putting messages of your own onto the CANbus can make your car do really interesting things that the factory did not intend...

mverhagen wrote:

 The dashcam had a problem and the fuse blew. 

That is one h*** of a problem.  It is hard to see how a dashcam, even a malfunctioning one, could pull that much current. 

Perhaps one does not wish to confess a sin.     Come on, you are among friends, you can tell us what really happened.  We won't judge, and it might help us help you.  

But with just the info you provided, I would say that perhaps you blew not only the fuse but also a connection in the loom  Perhaps just a lead off the back of the fusebox, or maybe just slightly scorched the fuse holder tabs.  Or you bent something while inserting/removing the piggyback (I hate those things) and/or your test leads.  No greater mystery here though, IMO, and maybe not worth digging further into the wiring.

But I would be careful that "the dashcam" didn't have any more whoopsies... after all, there are only so many fuse spots one can blow up before something serious goes bye-bye.