| The code means that your fax machine detected a busy signal. That could be because on the other end a voice or recording picked-up instead of the fax machine. Or, on your end the number is not being entered correctly. For example you might be leaving off an area code when it is required, or some other dial problem is occurring.
An easy test is to dial from a phone (preferably one connected to the fax line) and call the fax machine on the other end and see if you get through. If the other end picks up normally you will hear the screeching noise of their fax. | 
Linear Mode
