There are two default passwords for the D9858 receiver --- 1234 and 8390. If neither of them work, then it can be assumed that a user has accessed the password menu, and changed the password. In these cases, you may be able to have the receiver unlocked via the satellite signal. The programmer must have the ability to send ADPs to the receiver (ie. the receiver must be in the programmer's database).
Otherwise, the only other option is to send the unit back to the factory for re-programming.
If either '1234' or '8390' will not work, then we can conclude that it must be a unit pre-programmed with a custom password. Certain programmers (eg. A&E, Hallmark, Scripps, etc.) have units with custom passwords. In these cases, the only option is to work with the programmer to have the unit unlocked. This may either be accomplished via the satellite signal, or the programmer may be able to reveal the custom password. Cisco is not at liberty to disclose these passwords. In order to determine if you have one of these units, please contact Support at email@example.com and provide the UA/TID number of the unit.