Hi Caio,
I am not familiar with the VPW protocol, I have asked the FAE of automotive, the VPW is a High level protocol for automotive monitoring by the Car manufacturer. After searching the website, I found a lot of doc including application not, hope it can help you.
http://tinyurl.com/hfzqem5
For detailed technical problem, pls tell us detail, for example the part number, the peripheral, the tools you are using, the concrete problem you have... so that we can support you.
BR
XiangJun Rong