RomRaider

On my VC264, I've got 2x 8x8 maps directly after my mMADVTRMH and 1x 8x8 map directly after mMADVTRMR. They're all filled with 64 (0x40) values.

I'm guessing/hoping that they're some sort of additional multiplier or adder for the timing trim maps. I'd like to find out for sure because my ROM comes with 2 trim maps with identical values and I always presumed that they're low temp and regular but they're actually high and regular octane maps which would be extremely handy. I've checked out as many BitSwitches as I can find that are checked, related maps seem to have data in them and I've got some handy RAM addresses to monitor to see if the high/regular octane judgement is working. The main thing now is working out that these extra maps do.

Anyone able to look over this and tell me what these extra maps currently filled with 64 values do? The extra ones are in the bottom of the two function graph windows.

The other thing I'm struggling to confirm is:

mfREGGASI (0x80 bit in mIDOS5 on ZB060) - Regular adaptation car specifications choice flag. The contents of mIDOS4 and mIDOS5 do not seem to match between ROMs so without documentation, it's pretty challenging.

TB48DEs get best results with 95 RON fuel but it's very common to only get access to 91 in remote areas commonly accessed by these vehicles so I'm determined to get to the bottom of running both maps as intended with reliable knock control. At the moment we need to bring a laptop and apply a -3 overall timing correction if we need to run 91 which sucks!

The other question I have is with this item:

mfKNKTYP2 - Single 2 gain, twin 2 gain choice flag

Is this a single vs dual knock sensor switch or is it a single vs dual trim map switch?

Thanks in advance!

I'm really desperate to get my regular and high octane maps working. I've spent dozens of hours going through and labelling ZB060 stuff in Ghidra, finding the same/similar functions in VC264 and labelling what I can in there and defining in wols.

I'm still very lost to be honest. It's still not clear where the mfREGGASNI flag is nor where mSpecADV is and whether the mfFKNK, mfFREGDT, mfKNKTYP2 and mFFULTRM flags reside on the same bits as ZB060.

I've stumbled across all of these as related to regular vs high octane judgement and have identified some that will need changing to make it work properly but I know this is not everything.

mREGJG
mNCHK
mNCHKC
mADVDLY
mADVN1
mADVN2
mADVTP1
mADVTP2
mMKLMRTH
mMKLMRTR
mADVWA
mADVWB
mREGJG
mREGJH
mREGJL
mDADV
mDRET
mDBETA
mMKLMRTH
mMKLMRTR
mDADV
mADVWA
mADVWB

I know I should let go and forget about making this work but I just can't. I want the functionality so bad but I'm going round and round in circles trying to get any further.

If anyone familiar with disassembly would like to make a bit of money and learn more about the knock learning and octane judgement on these Nissan ECUs, please let me know!

From what I can gather, Learning values vBETAA through vBETAC are used to influence vBETAD which is the value used to decide whether or not high octane fuel is present. It looks like if vBETAD falls below mREGJL, it kicks into the regular octane map. Once vBETAD gets back above mREGJH, it goes back into the high octane map.

I think mREGJG "A weight coefficient for the BETAD calculation" is potentially an important one too. My stock value is 0 but ZB060 is 255. I'll have to check some other ROMS that have working high/regular octane maps and see what their mREGJG values are.

It's prob best to continue here:

viewtopic.php?f=65&t=18538