AJLElectronics:
I think you are correct, it is Enable active high and the SEN/STA goes low for clear to send. I did manage to destroy a TH3122 myself and it had those symptoms, plus heating up very fast. I think that I would be setting the TH3122 up on its own and see what is happening "bareback".What are you going to do with your board?
If you want to send me a PM, I can share my circuit diagram etc with you. I now have fully working Melexis and MCP version prototypes. I am just refining the software a little now before committing to PCB manufacture.
I have a Z4 with DSP that the OEM radio stopped working. I was able to put an aftermarket radio in the front, but in order for the DSP to activate and play music over speakers the broken radio still needs to be wired into the IBUS system in the trunk. I want to replace the OEM radio back there with a small board to emulate the OEM radio so that it activates the DSP and my aftermarket radio can use it without the OEM one sitting in the trunk.