A fellow in the b5 forum seems to believe so, yet I have heard nothing to back up this claim. Please shed some light upon this.

The block in question is block 003.

Specifically the 1996-1997 12V V6 ECU's made by Hitachi. These do indeed give goofy data when you try to view or log more than one group. This is a bug in the firmware of these ECU's. Audi would never have caught this bug because to this day, their own tool cannot display more than one group at a time and can't log measuring blocks at at all.

FWIW, this issue is documented here:<ul><li><a href="http://www.ross-tech.com/vag-com/audi_issues.html#HitachiOBD2">http://www.ross-tech.com/vag-com/audi_issues.html#HitachiOBD2</a</li></ul>

Some newer ECUs are capabale fo more than 30 samples/second.

The groups are what the groups are, again this is a function of the firmware in the ECU and how Audi chose to organize the data.

-Uwe-

If it takes X time to read one group from the ECU, then it takes 2X for two groups and 3X for three groups.

But this has no effect on the accuracy of the data per se (unless you have the wonky Hitachi 12V ECU).

-Uwe-