Nothing else in the application event log on the passive node. just this error scrolling:

initerrlog: Could not open error log file 'F:\MSSQLxx_xx.MSSQLSERVER\MSSQL\Log\ERRORLOG'. Operating system error = 3(The system cannot find the path specified.).

in the system event log on the passive node, I also see these errors periodically:

The SQL Server (MSSQLSERVER) service terminated with service-specific error %%17058.

The SQL Server (MSSQLSERVER) service entered the stopped state.

The SQL Server Services for the MSSQLSERVER instance are stopped and set to manual as they should be when the resources are all active on the other (active) node.