All Legacy engines default ID from Lionel is 1.  99 is effectively an "ALL" function.  Using ENG 99, all Legacy engines on the layout regardless of their ID made after around 2010 will respond.  Be very careful using ENG 99.

Thank you.

Here is what happens if you address ENG 99 with power to all tracks and blow the whistle / horn …

@John Capp posted:

Thank you.

Your welcome.  Maybe I should say " All Legacy engines default ID from Lionel should be 1.  I suspect there maybe unintentional exceptions.

In the early days of Engine 99 being loaded before it's functionality was widely known we ran a new Milwaukee S3 right off Norm C's turntable bridge.  See Norm had his turntable programmed to Engine 99.  Went to spin the table using 99 and that S3 sprung to life.  The lesson was quickly learned.

@MichRR714 posted:

In the early days of Engine 99 being loaded before it's functionality was widely known we ran a new Milwaukee S3 right off Norm C's turntable bridge.  See Norm had his turntable programmed to Engine 99.  Went to spin the table using 99 and that S3 sprung to life.  The lesson was quickly learned.

YIKES!