My NYC Mohawk PS2 was always at engine address #4. I have 3 remotes and 5 engines. Addresses from #'s 1 to 5. The Mohawk address reads #4 for 2 of the remotes. When I powered on the problem remote the screen displayed an (L) at upper left for lash-up at 0 mph. No engine was indicated. I shut down, then powered up remote again and the same. Don't recall if there was an engine name on the display screen but there was the #4. Function keys were not shown on display. I never created a lash-up. Then I went to engine setup, added the engine back to the remote. It took the address #6. Then I used the edit engine address function to change to address #4. The #4 was not to be found which usually happens when that address is occupied. So I deleted that engine from the other 2 remotes and tried again to edit address on the problem remote. Same thing happened...no #4. Deleted on the problem one, added it again and won't take address #4 but went back to #6. Thought I could delete from lashup but didn't work because message appeared "no engine to delete". The Mohawk works fine as #6. But it's bothering me that I am unable to go back to its former #4 address. Silly I know, But any help is most appreciated. Thanks, Fred