We measured the Honda Odyssey with the CAN test box, connected to pins 6 and 14, but none of the lights on the box turned on or blinks, showing that it is not connected correctly. On the waveform we saw that there is voltage but without current. But there is no problem when we used the CAN test box with another car, and the signal is received normally.
We tried to measure the OBD directly but still didn't work. We also check that Odyssey is parallel connection, so there should be no need to activate the gateway.
I think in this instance it would be good to attach a scan tool to the CAN test box and access the vehicle. It looks very much like the VW network where there is no communication till a request is made.
If the test box and the scope detect CAN on another vehicle things are pointing towards the vehicle side.