So, the oscillator is optional on SC13 and the loader does not use it at all. This explains why the loader works and the firmware does not. For whatever reason, the firmware is not happy with your oscillator.
CAN will 99.9% work with no oscillator. But you should have an oscillator and it should work. I am also curious myself if there is something we can do to make it work on our end or you have hardware issue.
Our product has basically 100% uptime on the CANbus and we’re not using any external circuitry to make it work - what are you using the oscillator to do? Genuine question, figured if there is a better way to do what we’re doing it’d be good for me to know.
CAN does error handling and resync to the bus automatically. You will just fine without crystal but the higher the clock and more picky you want to be the more you need the crystal. It depends on how picky you want to be.
Your schematic doesn’t show any capacitors to ground for the crystal so that is likely why it fails to start oscillating. The GHI dev board shows these to be 10pf. Check your crystals requirement.