Thread: VPW 4X high speed

Is this for a commercial or a hobby project?

We can easily add VPW 4x support to OBDLink. Unfortunately, there are so many other projects on the table that it may take a while, unless someone can demonstrate demand for/put some actual $$ behind this feature.

Vitaliy

This is for a personal project, but if it pans out, it will allow for reprogramming GM Obd2 Pcms, which then would open up the market.

I have found one that may work for it, hoping to order soon to test.

http://www.obdscan.net/APEX.pdf

Originally Posted by planethax

This is for a personal project, but if it pans out, it will allow for reprogramming GM Obd2 Pcms, which then would open up the market.

I have found one that may work for it, hoping to order soon to test.

http://www.obdscan.net/APEX.pdf

I doubt it supports VPW 4x. This is the only only mention in the datasheet says:

"Future VPW 4X Enable – can be used to
control the 4X pin of the MC33390 J1850
VPW driver"

There's no mention of a command that would let you switch to 4x.

By the way, we bought a sample not too long ago and it looks homemade. I would guess (based in part on the "Copyright 2006" text and the hand-assembled look) that Harrison R&D sells fewer than 100 units per year.

Best regards,

Vitaliy

Well according to Dan
"The VPW 4X has not been really tested, we just don’t have the GM ECU data to allow us to test."

I have re emailed to find out for sure.

A device that can enable the 4X Vpw can reflash GM Pcm, which in my opinion be a HUGE selling feature.

Originally Posted by planethax

Well according to Dan
"The VPW 4X has not been really tested, we just don’t have the GM ECU data to allow us to test."

I have re emailed to find out for sure.

A device that can enable the 4X Vpw can reflash GM Pcm, which in my opinion be a HUGE selling feature.

Which software would you use for reflashing?

I am currently developing my own, so far have the rutine for getting the Seed/Key pair.
Need a few more pairs to hopefully hard code the algo to the app.

Originally Posted by planethax

I am currently developing my own, so far have the rutine for getting the Seed/Key pair.
Need a few more pairs to hopefully hard code the algo to the app.

I see.

I'm still not sure how you're supposed to switch APEX to VPW 4x mode. Is it some kind of undocumented command?

Vitaliy

Originally Posted by Vitaliy

I see.

I'm still not sure how you're supposed to switch APEX to VPW 4x mode. Is it some kind of undocumented command?

Vitaliy

R&D are currently doing some testing for me and I hope to hear back with in a few days.

They are going to be testing the 4X mode.

According to the PDF writeup, they are using the MC 33390 as their VPW transceiver. While this transceiver supports 41.6Kbps send and received, it only supports block mode in receive mode. While you could flash a PCM while not in 'block mode', its going to take pretty darn long. They will need to use a MC68HC58 as their transceiver. (for example).

This part is out of production I believe; therefore, at some point quantities will run out.