senordingdong wrote:
Ive actually done quite a bit of research into it, and it turns out that while its relatively trivial to dump and modify the chip data, it is not possible to rewrite it.
It is a OKI MCU that is only writable one time, and does not have any interface for external memory. Since it is something of an obscure chip the pricing is very high. lowest i saw was around $100 with significant lead time from china. So, while totally possibly, not cost effective unless you are certain of your tune, because you don't get a second chance if you messed something up.
I read through the data sheet several times hoping for something but it seems pretty cased closed on this one.
There are several similar OKI MCUs that have EEPROM memory, but they don't appear to be pin compatible with this MCU.
you are seeing the same things seen 15-20 years ago, some parts were available back then, but the ease of tuning OBD1 ECUs and adding a simple conversion harnesses was so much easier.
tenshi_R wrote:
isnt it possible to use an adapter if pins dont allign?
maybe something similar to demon board that emulated the original chip?
as far as 2004-up ecus theres away to tune almost all of them
check out tactrix.com and
http://ecutools.eu/chip-tuning/adapters can be created(which is not easy) plus most of the MCUs out there today have some ports/protocols that do not align(depending on which chip you choose of course) so an adapter circuit would likely have to be created as well.
GonzoWerkeAG wrote:
Big 3 guys can buy tuners that plug into the obd2 port...BUT, they just modify signals, they don't actually edit maps(to my knowledge)
OEMs and their tuning houses have emulators or at the very least CAN tools that modify the maps real time (for modern cars)
There is some evidence in our OBD1 cars that they had something close to this level even in the early 90's.