"Maintenance Required"

You can check the maintenance status in the "more" soft key list, usually at the end of the list, about key number 37 or 38.  It'll say maintenance required in x miles.  There is a reset function on that screen to reset it back to 1000 miles.   

The maintenance required is (as Cab mentioned) that described in your owners manual. 

It's just another nice feature of DCS; reminding us that it's time for the annual lubrication and cleaning.  It will keep showing up until you go into the soft key list and reset it. 

I've looked throughout Barry's book (vs 1), as well as MTH's DCS guide and the engine's owner manual and can find no reference to the code on the remote saying the engine (GS-4 Daylight) requires maintenance

 The DCS O Gauge Companion 2nd Edition, page 149.

I find that message comes up whenever I try to start up o loco that sitting on an unpowered track.

How do you start up an engine sitting on a unpowered track?

You don't.  Note I said "try."  If I want to start up a loco, and forget that the block it's in is unpowered, I press "startup" on the remote.  The remote sits for an eternity, or slightly less, and then often comes up with a "maintenance required" note.  Now it may be correct that I may need mental maintenance, but I'm sure MTH intendsed this message to relate to a locomotive..

RJR; if you select an engine on an unpowered track from your active engine list, and press start up, the messages you should see are "check track" followed by "engine not on track".  

If the engine is in the inactive engine list, you should see "engine not on track" and it won't come out of the inactive engine list until you power the track(it starts up in conv). Then you can press start up key to gain control in command mode. 

The only thing that should activate the "maintenance required" message is miles since the last time it was reset.  

If you are seeing the maintenance message under the circumstances you describe, you may need to call the Geek Squad to work on your DCS system.

Why?  Doesn't affect operations.  Trains run without control problems, which is more than many mnaking posts on the Forum can say.

Gentlemen,

   Read the Maintance require section on Page 149 of the DCS Companion vol 2

it fully explains your problem and how to reset your hand held remote.  Barry's

discriptive wording is simple and perfect.  There are few things that Barry did not cover in his book, have been giving it study over the past two weeks and it answers just about every DCS question an operator/builder can think of, I wish to God he would have written this books when I 1st started into DCS, it saves time & money both.  Wish I could get Barry interested in running Tin Plate so he would investigate old and new Switches that accommodate DCS Tin Plate Trains and how to set them up correctly.  Would love a section in his book that talked about DCS Tin Plate Switches how to set them up and what old and new Tin the swtches will accommodate, he does cover all the other types.

Its an abuse of Tin Plate Runners to leave this kind of technical information out.

Any one who does not own & operate at least one good Tin Plate Train is a Train abuser, I know it.

PCRR/Dave