[Subscribe to Daily Digest] |
I have an EPROM emulator that cost a couple of hundred UK pounds. If strapped for cash, I could have built something to do the job for less than £30. It would be more than adequate for the likes of LH and many other fuel injection systems. You don't always need the most expensive equipment available, and if this guy is into embedded software in any way (many people are, even as a hobby), it's quite possible he has access to some fairly inexpensive equipment of this type. The T5 would be much easier than LH, as the required hardware would be a lot cheaper (most of the required logic is built into the CPU and most of the rest is just software on a PC for example). The T5 hardware is very run-of-the-mill stuff by modern standards and proprietary Saab equipment is definitely not required for reprogramming. The T7 is unlikely to be much more difficult to access - standardisation is regarded as a good thing for industry these days.
However, as you rightly point out, the hard bit is in knowing *what* to program in there. In addition, the software within the T7 is reputed to be hard to modify effectively. I don't know the reason for this, but I suspect that there are a lot of interrelated values within the ROM, the relationships of which are hard to determine without inside knowledge from Saab or its subcontractors. The product at the link you provided appears to contain software that knows about the fuel and ignition maps of particular systems and this expertise is what would command a premium. A lot of the cost of an ECU upgrade goes towards paying for the up-front cost of extensive development time and I wouldn't criticise people like Abbott or Maptun for the prices they charge. There are people on this board who have worked out how the fuel maps in LH work, though, by comparing the ROMs of different applications of the same system.
However, my point is that the actual reprogramming of the unit is no big deal and requires neither a genius nor thousands of pounds' (or dollars') worth of equipment. I should point out that I have no experience of developing engine management systems, nor have I ever seen a T7. My job, though, involves developing microcontroller systems and I have had a good look inside a T5 which, as I say, contains very standard hardware (and not much of it). It is what our marketing people would describe as a "cost-sensitive" application and appears to be quite an effective design in that respect.
posted by 80.2.252...
, Fri, 31 May 2002 07:50:11
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
