I have a CAN device (PiCAN2 for Raspberry 2) that fails to send or receive CAN messages. The device itself is working, but no CAN messages are received or sent. Termination resistance is ok, so I checked the voltage. Between GND and CAN HIGH, there are 1.3 V and it drops to 1.2 V when I try to send messages. Between GND and CAN LOW, I have exactly the same values. Next I checked the resistance. Between CAN HIGH and CAN LOW I have 47 kOhm and between GND and both CAN wires I have >200 MOhm each. So the resistance seems fine. Is it possible that I have an electrical issue in the PiCAN2 that causes the voltage problem, even though the resistance is fine? Or could it be a supply voltage issue? The PiCAN2 sees a supply voltage of 4.8 or 4.9 V, which is slightly lower than the nominal 5 V.
Edit: The device had been working fine until this morning. In case it is an electrical problem: What could be potential causes for this to happen?
Edit 2: [Solved] I replaced the PiCAN2 module with a new one and it works now. So it was indeed a hardware problem. The module must have taken damage when I was working on its solder bridges. However, it kept working properly for a couple more days and also the software was running smoothly at all times, which made this one a bit tricky to troubleshoot.