As shown in my parts book
12L is 4 cylinder 2.5 200 TDI
17L is 4 cylinder 2.5 300 TDI EDC Manual
19L is 4 cylinder 2.5 300 TDI EDC Auto
21L is 4 cylinder 2.5 300 TDI EGR Manual
22L is 4 cylinder 2.5 300 TDI EGR Auto, also 3.5 EFI Manual
No engine build dates are shown.