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Q45 8bit gear fuel maps causing comms issue...strange..

Posted: Mon Jan 18, 2021 8:45 am
by 450zx
Hi All,
My first post so go easy on me.
I have finally worked out what has been causing an upload/comms issue for pretty much the whole time I've been setup. This issue rears it's head whenever I upload (to ECU) the gear fuel & gear knock fuel maps...after many of hours of resoldering and head-scratching!!
I have been trying to copy 'reasonable' fuel maps into these tables in-case these get accessed. I don't believe they would have, as the engine would not run for long (Check images).
Anyway, whenever I try and upload to the ECU either of these 2 maps from any reasonable tables, I instantly get a comms fault that will not clear unless I power down the ecu for a good few seconds (and sometimes restart nistune). I am guessing something in the addressing for these tables is incorrect.
As a work-around I have just uploaded all but these 2 tables whenever I make changes. They are not pretty, but guessing they are not accessed anyway, so will leave as is.
Keen to hear if anyone else has had this issue.
Cheers,
Lincoln.
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Re: Q45 8bit gear fuel maps causing comms issue...strange..

Posted: Mon Jan 25, 2021 12:22 pm
by Matt
Looking a bit into this, since been a while (6 years) since I've worked on the firmware

Basically there was no spare space to put all of the comms code in Q45 8-bit, so we had to remove those maps and put our code there
UPGEAR_HIGH_FUEL,&H6C00,16,16,256,1
UPGEAR_REG_FUEL,&H6E00,16,16,256,1
Area allowed to change is E900-FFE9

That is why it looks funky

EC00-ECFF, EE00-EEFF addresses are the ones used for this. Opening up one of the ENT files, these were 'reused' for adding the Nistune consult communications code.

There is nothing stopping you accessing these maps, but we can remove from the display (and upload) by default by removing the top two lines

Attached are the updates (unzip into your Documents\Nistune\Address folder). If Q45 with an emulator, then these can be uncommented

From memory, these tables were not used from factory. I'll check that now...

1. Address $005E #80 set to use the upgear tables.
2. Speed x Value FFC8 (gear coefficient, same as Z32) compared against RPM to set clear/this address
3. Value of FFC8 is 0 (so tables not used)

So upper tables not used, and just use attached address file so they don't display/upload

Re: Q45 8bit gear fuel maps causing comms issue...strange..

Posted: Thu Jan 28, 2021 8:54 am
by 450zx
Thanks Matt!