Based upon the size and page-count (1232) statistics, i think that's really the 2003 manual.
(the download is not progressing for me, so i can't check the document itself (yet))
Its original name was 21105-va_intlpdf.pdf, and was frequently seen as 05-Sprinter-Service-Manual, hence the confusion.
The 2004 manual has more pages (1276), i would expect that trend to continue (2006 is 1458 pages)
The way to verify the manual's date is to look at the Acrobat File/Properties of the PDF file.
The 2003 manual was created in 2003. But that requires an unmodified file.
added: although whoever packaged that PDF file gave it a new creation date (2016), the "how to decode a VIN" has 2003 shown for the "year" field. I see that the 2004 manual
also uses 2003 in their example, so i can't say that that's definitive (2006 uses 2006, and i don't have a "for real" 2005 manual for cross-check)
I'll look to see if they mention a resonator in the intake plumbing and/or an in-tank fuel pump....
Either way, the 2003/2004/2005/2006 are "close enuf" for most work...
Yup... it's the 2003 ... on page 14-13 (acrobat page 841) they flat-out say that there's no low-pressure pump in the fuel tank. On page 9-6 they speak of (and show in Fig 3) the vacuum line driving the turbo actuator. The 2004 manual has neither of those two characteristics.
--dick
p.s. this link:
http://www.diysprinter.co.uk/reference/2003SprinterManuals.zip
fetches the 2003 service CD ... including the service manual (with the "tree" index structure intact) plus the subsidiary Powertrain, Transmission, Chassis and Body diagnostic manuals.