@Werner_E any thoughts on this on why odesolve in Untitled-16_MCP9 does not work when Id function is used? And Id function is used in find block and not directly in odesolve block (but as I showed in Untitled-18_MCP9, even the Id function is used in odesolve block odesolve block seems to work), and only the result of V3(t) in Untitled-16_MCP9 is used then in odesolve block...