Electronic Alarms and Home Security Devices - simon 3 keypad problem

Installed a basic Simon 3 system a few months ago and all worked fine until the QS1500 keypad batteries ran down. Keypad would no longer respond at all even after new batteries installed.
Purchased a new keypad which seems OK (with beeps and all) but can't get it programmed into the main unit. Attempts to add this sensor into the main unit always end with "failure" announcement. Tried different locations but no better results. Any ideas?

List out what you are doing to try to enroll this device. Often it's some small step that's being left out that is the problem.

In programming mode I press "add" then press "sensor/remote" then trip keypad w/6 pushes of "lights off button"- keypad and main panel each respond w/beep (which leads me to believe that panel is sensing the keypad) and then I scroll "sensor/remote" to select "touchpad remote" - then pressing sensor group 01 and "done" results in "failure" announcement. All seems to be according to instructions. Tried entering different sensor group numbers to same effect Panel version is 4.1 and keypad is same and of course new batteries

Check the part number on the keypad. You may have gotten either the non-dialogue version (does it have an antenna coming out the top?) or the Simon XT version....

yes, there's an antenna. Don't see a part # per se.
there's: Tx ID KO3FFA9110F9D48
DL 03FFA9110F9D4F8
and

FCC ID: B4Z-839-TWTP
IC: 1175-839TWTP

No idea what any of these numbers mean

yes, there's an antenna. Don't see a part # per se.
there's: Tx ID KO3FFA9110F9D48
DL 03FFA9110F9D4F8
and

FCC ID: B4Z-839-TWTP
IC: 1175-839TWTP

No idea what any of these numbers mean

I think you've got the XT version...
Does it talk at all? If so, is it a female voice?

male voice. Unit appearance and literature looks exactly like the original unit...