0 - 1 of 1 tags for not enough information

I can connect to a Teradata db instance using a DSN entry.  When I reference that same DSN entry in an adodb connection string the .Open command generates the error "Not enough information to log on"  
 

    Dim conn As New ADODB.Connection

    

    conn.ConnectionString = "DSN=TDFADS_SYS" 

    conn.Open