We managed to hookup our hardware by following suggested design, and we wanted to use only CAN protocol. And on the breadboard with STN1110 DIP package everything works great on ECUSim 2000 simulator and on a actual car. BUT, when we designed a PCB and moved to QFN, we are getting weird messages from STN1110 chip.
For example, we have the same test environment for breadboard and for actual PCB, but for that PCB we just ended up with these messages from Torque "Identifying ECU" and "Check if ignition is on" (and it is on). With breadboard everything is fine, we are getting our readings.
Also, if we put on a side Torque, and if we try to communicate directly with STN1110, if we send for example ATZ, we are getting response valid response. But if we try to run for example some command, let's say 0902 we are getting from PCB when we run the command via FTDI: BUS INIT STOPPED BUS INIT FB ERROR (this is from PCB (QFN version of STN1110))
And we triple checked PCB design and all the traces between STN1110 and MCP2551 and MCP2551 and a simulator \ car, and everything is fine, we even replaced MCP2551 just in case but same error.
Any suggestion what else we can try?