Thanks for the responses. So if the '02 ECU definitely does not work, and an '03 ECU doesn't fix the problem what else could it be?
Hopefully kd7iwp will find an easy fix in the wiring somewhere that will make the '03 ecu work. Maybe then he can swap the '02 ecu back in just to confirm it definitely won't work.
I also saw a reference (earlier in this thread?) that rocketchip programming will enable ESP on ECU's not so equipped. Any confirmation on that?
I REALLY REALLY want ESP, so I love this thread. I spent a whole day at the junkyard pulling a complete uncut harness out of an '03. I'm doing a Climatronic retrofit as well, so while the dash is out... ;-)
Thanks to everyone who's contributed to this thread, especially the OP.