D23 is a D22 series 2 or Mach 2 for the Pom's.
UK D22 Series 1 ran the TD25Ti.
Series 2 ran the Non CRD YD25DDTi.
There is a service manual in the D22 General section.
Aussie D22 Series 1 ran the QD32, VG30E from memory and the KA24E, VG30E and the TD27 was available in the 2WD.
Series 2 and 3 ran the ZD30DDT, VG33E and the VG30E and the KA24DE in the 2WD (NZ had the YD25DDTi Non CRD in the 2wd). (US only had the KA24DE and the VG33E). (African markets had the Z24S and the NA20S available to). Grey interior and dash.
D22 Series 3 had the (ZD30DDT in 4WD), (VG33E till 2005) and KA24DE in the 2WD and I think the VG30E was available in that year to. Drivers airbag standard and passenger airbag optional. Black dash and different seat material.
Series 4 started in 2008, YD25DDTI CRD as the only engine available in Australia. Same as above interior wise.
Series 5 was late 2009 with the Thai built D22, longer tray and different door handles and slightly different door trim. Same abover interior wise.
I dunno if Id consider the Japan built 2012 D22's as Series 6.