059 DME is adaptive...also posted in Tech area with links...

Discussion pertaining to positive pressure E28s.
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russc
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Post by russc »

For the curious, I reverse engineered the phantom part on the digital side. There is a IC near the 8051 CPU that had labeling unknown to me, see earlier thread:
059 thread

Upon further inpection, the part is 256x4 SRAM that has battery backup from the no-switched 12V input. So, up to 256 nibbles can be stored for adaptation. These are lost when the battery is disconnected. Now I can rest.....I was tracing signals till 3:30AM last night, got up at 8AM and started back in.

For the technically curious, heres the data sheet:

CPD1822 256x4 SRAM from RCA, now Intersil

RussC
Jeremy
Beamter
Beamter
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Post by Jeremy »

So it does have a memory? Interesting . . . I guess the next task would be to somehow figure out what it remembers!!

You're not going to rest until you know the 059 better than anyone, are you? :) Not that there's anything wrong with that.

Jeremy
russc
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Post by russc »

[QUOTE="Jeremy"]So it does have a memory? Interesting . . . I guess the next task would be to somehow figure out what it remembers!!

You're not going to rest until you know the 059 better than anyone, are you? :) Not that there's anything wrong with that.

Jeremy[/QUOTE]

yes, it does have memory. What it stores is drive specific data and trim values I'll bet. I remember JimC saying the the DME will increase fuel/timming if it sees lots of WOT conditions, and then will lean out if it sees lots of cruising.

Um, I'll never know as much as SteveD or JimC. I believe at the least these guys were given from BMW or developed themselves tuning tools to do this stuff easily. Maybe even has source code.

RussC
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