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Found - LT Fuel Trim Control !!!

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Old May 13, 2009 | 01:41 AM
  #31  
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Yeap. As soon as you see the subroutine that the maps were found in it is very obvious they are RPM. MUT 21 is what is used for injector duty calculation amoung other things, and is the exact same calculation used for any single number (1D) RPM adjustments. It is just odd that is uses unit8 rather than uint16, which is why I had to create a new scale for it.

**Ã'
ROM:0001190A loc_1190A: ; CODE XREF: LTtrim2_118F0+16j
ROM:0001190A extu.w r13, r0
ROM:0001190C mov.l @(h'150,pc), r10 ; [00011A60] = LTtrimRPM_3A1D
ROM:0001190E mov.b @(r0,r10), r11
ROM:00011910 extu.b r11, r11
ROM:00011912 mov.l @(h'148,pc), r10 ; [00011A5C] = RPM1Ds_FFFF6960 ; <---- MUT 21
ROM:00011914 mov.w @r10, r10
ROM:00011916 extu.w r10, r10
ROM:00011918 cmp/hs r11, r10
ROM:0001191A bf loc_11928
ROM:0001191C mov.l @(h'114,pc), r10 ; [00011A34] = MUT19_FFFF6A0E
ROM:0001191E mov.w @r10, r0
ROM:00011920 or #h'10, r0
ROM:00011922 mov.w r0, @r10
ROM:00011924 bra loc_11932
ROM:00011926 nop
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Old May 13, 2009 | 06:50 AM
  #32  
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yeahhh.....oooooK

So any way...speak english please....HAHA

I feel so stupid now.
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Old May 13, 2009 | 02:43 PM
  #33  
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I dont know some of it either, I am not that nerdy. But you can see the references for the RPM map and MUT21. You may be able to log some of what is happening by using MUT19 which is obvious in there too. Set up a new data item in Evoscan and use Request 19, and set the eval to "x bit 16".

My initial though was that they use the same Y-axis data as the Hz control, but reversed. What had me thinking is that there is a timer control somewhere that I have not tracked down. LT trims need a certain amount of time under the correct conditions before they start, and that is something I want to find.
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Old May 13, 2009 | 02:45 PM
  #34  
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Yeah there is some delay before the LTFTs will start to adjust.
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Old May 20, 2009 | 05:27 PM
  #35  
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Hey guys, I'm having a problem with my Mid Trim adjusting at idle. I'm guessing it's because I'm seeing airflow of 50-56Hz at idle. Anybody got info for 96420008? I'm thinking about switching to 96420011...anything on that one?

Last edited by MasterNater; May 20, 2009 at 06:15 PM.
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Old May 21, 2009 | 04:00 AM
  #36  
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All roms have it.

96420008, the Hz map is at 35e5. I dont have a 0011 rom to check, but being the same series it is most likely the same address.
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Old May 21, 2009 | 04:32 AM
  #37  
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Originally Posted by MasterNater
Hey guys, I'm having a problem with my Mid Trim adjusting at idle. I'm guessing it's because I'm seeing airflow of 50-56Hz at idle. Anybody got info for 96420008? I'm thinking about switching to 96420011...anything on that one?

Your BR MAF pipe and 272s are causing the idle problem. I would assume you have your idle RPM set pretty high. If you can get it lower, like right at 1000 RPM, you should see your LTFT Low start to adjust. You need the Hz below 44Hz.

Buschur always recommends running an AEM with their intake becasue of the idle problems it creates.

MAF scaling may help too. Only adjust the values in the 50Hz and below though. Most intakes I have delt with have needed these values increased.
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Old May 21, 2009 | 06:18 AM
  #38  
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any luck finding the addresses for the 96260009 rom? i have a red and revolvers with inconsistent idle and sputtering starts at times. likes to spend most of its time idling around 50Hz but does see 43Hz as well.

Originally Posted by Mattjin
All roms have it.

96420008, the Hz map is at 35e5. I dont have a 0011 rom to check, but being the same series it is most likely the same address.
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Old May 21, 2009 | 07:49 AM
  #39  
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Originally Posted by Mattjin
All roms have it.

96420008, the Hz map is at 35e5. I dont have a 0011 rom to check, but being the same series it is most likely the same address.
Thank you. I tried that address yesterday, but it didn't work. I must have messed up with the copying and pasting somehow. Works like a charm now

BTW - it also works for 96420011
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Old May 22, 2009 | 02:30 AM
  #40  
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96260009 is the same - 35e5
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Old May 22, 2009 | 04:06 AM
  #41  
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From: Lattitude 48.38°, Longitude 17.58°, Altitude 146m = Slovakia, for common dude
I have been asked by Mattjin to have a look at fuel trims.
I have come across MUT_D, I believe it is offset constant (128[h'80]) for MUT_C
and according to dissasy never changes.

Moreover I have found that value shown at OBDII as LTFT is calculated from
MUT_50
scaling is
OBDII_LTFT => ((MUT_50/4 - 32) * 100/128

It seems that MUT_50 is calculated purely from MUT_C.

I have found also that the scaling for STFT is wrong
OBDII_STFT => ((MUT_F/512 - 122) * 100/128

Last edited by acamus; May 22, 2009 at 06:59 AM.
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Old May 22, 2009 | 04:35 AM
  #42  
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It is like the more you all find....the less we really know. It amazes me that we can tun our cars so well with the "limited" Ecu information available. Imagine what we will be able to do once everything is fully inderstood?
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Old May 22, 2009 | 09:05 AM
  #43  
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Originally Posted by acamus
I have been asked by Mattjin to have a look at fuel trims.
I have come across MUT_D, I believe it is offset constant (128[h'80]) for MUT_C
and according to dissasy never changes.

Moreover I have found that value shown at OBDII as LTFT is calculated from
MUT_50
scaling is
OBDII_LTFT => ((MUT_50/4 - 32) * 100/128

It seems that MUT_50 is calculated purely from MUT_C.

I have found also that the scaling for STFT is wrong
OBDII_STFT => ((MUT_F/512 - 122) * 100/128
So max LTFT values are actually ~ -25 / +24.804? Would it be "most accurate" to use the above equations for standard MUT (non OBDII) logging also?
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Old May 23, 2009 | 09:06 AM
  #44  
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thank you sir. here are the stock values. seems a bit higher than others.



Originally Posted by Mattjin
96260009 is the same - 35e5
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Old May 24, 2009 | 12:47 PM
  #45  
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From: Lattitude 48.38°, Longitude 17.58°, Altitude 146m = Slovakia, for common dude
Originally Posted by fostytou
So max LTFT values are actually ~ -25 / +24.804? Would it be "most accurate" to use the above equations for standard MUT (non OBDII) logging also?
for MUT_C,MUT_D,MUT_E
most accurate is here or written differently here

MUT_F, MUT_50
is above
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