Here’s all the programming info for the Icom U-16. (The H-16, V-100 and U-400 are programmed in the same way. There are some slight differences between the H-16/U-16 keypad and the EX-494 programming keyboard used with the V-100 and U-400.)
The H-16 can also be used to clone an H-16, V-100 or V-200; the U-6 will clone a U-16 U-400 or U-200. Appropriate clonig cables are required.
If the U16 has been made programmable by moving a jumper:
Hold FUNCTION KEY down and enter 159357 It’s now in programming mode. Exit with FUNCT-CLR.
If the jumper has been removed a colon will now show up between the Ch and channel number. You have only 30 seconds time between entries or the radio will time out and return to operation mode.
Function + 1 Encoder tones (1-37)
” 2 Decoder tones (1-37)
” 3 ?
” 4 Delta + / Delta – offset, 5 digits
” 5 Frequency, 5 digits (400MHz +)
” 6 ?
” 7 Sch. Ch. numbers. Allows alias ch numbers.
” 8 Transmit timeout enable.
” 9 TI, Transmit Inhibit
” SCAN Priority Scan/Ch Scan
” S.CH Channel Masking
” CLEAR End programming mode
Channel select: Standard method (up/down arrows or CH# + [ENTER])
Frequency: Hold [FUNC], Press , enter 6 dig freq, [ENTER], release [FUNC]
Rx CTCSS: Hold [FUNC], Press , enter 2 dig code, [ENTER], release [FUNC]
Tx CTCSS: Hold [FUNC], Press , enter 2 dig code, [ENTER], release [FUNC]
Offset Freq: Hold [FUNC], Press , use [#] for up offset, [*]
for down offset, then enter freq to offset by (ie: [#] 
    for no offset, [#]      for the
standard +5MHz UHF offset), [ENTER]
Timeout Timer: Hold [FUNC], , Release [FUNC]
Tx Inhibit: Hold [FUNC], , Release [FUNC]
Special Channel Number: Hold [FUNC], Press , enter the
special channel number (17-99), [ENTER], Release [FUNC]l
Data Transfer MASTER: Hold [FUNC], [BEEP], Release [FUNC]
Data Transfer SLAVE: Hold [FUNC] with power off, turn on, release [FUNC]