Originally Posted by scott@upsolute
The ECU's have different code, checksum location, map location, and also physical differences. The processors inside can vary as well...although most are the same for a given ME-level. A ECU for this car is probably $350-$500 if you hunt around...the dealer will probably want $700-$900.
With piggybacks you retain the stock ECU, even full-out replacements still require the stock ECU for other functions. Have look at the SMT-6 from perfect-power.
VAGCOM is VW/Audi specific, it goes beyond the basic OBD-2 required parameters and gives access to hundreds of sensors, values, etc., plus allows recoding of some items depending on the car...kinda like the "star" system MB has. The producers are working on a BMW-specific tool that will give advanced range of functions, no idea when that will arrive. Access to things like fueling are not allowed, the way they are stored in memory is not directly accessible.
I'd be very interested to see some logged data from your car. If someone is local to me we could try to make a few graphs as well.
The scan tools are well worth the couple hundred $$ for the data they can give you.
Thanks again for clarifying that Scott. If I can get an ECU for around $300 USD that's not bad when converted to GBP! I'll keep looking. I really just wanted to get hold of something with the same architecture as the Crossfire ECU so that I can see how all the I/O is mapped.
Yes, I did think that Vag Com was VAG specific and that VAG cars do make it slightly trickier to access the extended PID's. I assume you originally made the reference to it since you have a Passat yourself (assumed form the graphs you posted). However our cars aren't VAG so I don't see how VAG Com would be relevant in this case?
Yeah, spending a couple of hundred on scanning tools is not really a problem, although I have a homebrew setup that seems to work OK. I might run into problems with the extended DCX PID's, - we'll see.
As soon as I get some data logged I will post it here. I am quite busy with my 'real' job at the moment so need to find the time to fit it in. (I am away at the moment but just found time to log in on a client's PC!)
Cheers,
Simon.