HD ECM O2 AFR correct info inside
Tourer
Joined: May 2010
Posts: 348
Likes: 5
From: The mitten state
Jstreet,
The "cells" are the long term correction values that are stored in NVM when the closed loop learning is enabled. The table you explain that "applies" the adapt values is different in Harley software. The table is a percetage of a "nearby cell" value that would be applied to a "calibratable" cell number.
They are stored in a speed vs. load map. There are other tables that allow when and how much of a "near" cell is used in open loop. Typically the way those values are applied is if the "cell" value that would be used in open loop is adding fuel, the value will be applied. If the cell value is "removing" fuel, the value will ignored. It is safer to be too rich as opposed to too lean in open loop. And that is the way most folks use the long term memory correction to be applied during open loop.
And just as I'm sure Ford software does not allow "learn" during all facets of closed loop, there are instances when the system may be closed loop, without enabling the long term correction. So learning only happens when the engine is in "normal" operation. ( specific sensor inputs must be within a window to allow full learning!)
Does your software have a similar function?
The "cells" are the long term correction values that are stored in NVM when the closed loop learning is enabled. The table you explain that "applies" the adapt values is different in Harley software. The table is a percetage of a "nearby cell" value that would be applied to a "calibratable" cell number.
They are stored in a speed vs. load map. There are other tables that allow when and how much of a "near" cell is used in open loop. Typically the way those values are applied is if the "cell" value that would be used in open loop is adding fuel, the value will be applied. If the cell value is "removing" fuel, the value will ignored. It is safer to be too rich as opposed to too lean in open loop. And that is the way most folks use the long term memory correction to be applied during open loop.
And just as I'm sure Ford software does not allow "learn" during all facets of closed loop, there are instances when the system may be closed loop, without enabling the long term correction. So learning only happens when the engine is in "normal" operation. ( specific sensor inputs must be within a window to allow full learning!)
Does your software have a similar function?
Last edited by FBRR; Jul 23, 2010 at 09:26 PM.
Road Master
Joined: Jul 2008
Posts: 1,021
Likes: 2
Jstreet,
The "cells" are the long term correction values that are stored in NVM when the closed loop learning is enabled. The table you explain that "applies" the adapt values is different in Harley software. The table is a percetage of a "nearby cell" value that would be applied to a "calibratable" cell number.
They are stored in a speed vs. load map. There are other tables that allow when and how much of a "near" cell is used in open loop. Typically the way those values are applied is if the "cell" value that would be used in open loop is adding fuel, the value will be applied. If the cell value is "removing" fuel, the value will ignored. It is safer to be too rich as opposed to too lean in open loop. And that is the way most folks use the long term memory correction to be applied during open loop.
And just as I'm sure Ford software does not allow "learn" during all facets of closed loop, there are instances when the system may be closed loop, without enabling the long term correction. So learning only happens when the engine is in "normal" operation. ( specific sensor inputs must be within a window to allow full learning!)
Does your software have a similar function?
The "cells" are the long term correction values that are stored in NVM when the closed loop learning is enabled. The table you explain that "applies" the adapt values is different in Harley software. The table is a percetage of a "nearby cell" value that would be applied to a "calibratable" cell number.
They are stored in a speed vs. load map. There are other tables that allow when and how much of a "near" cell is used in open loop. Typically the way those values are applied is if the "cell" value that would be used in open loop is adding fuel, the value will be applied. If the cell value is "removing" fuel, the value will ignored. It is safer to be too rich as opposed to too lean in open loop. And that is the way most folks use the long term memory correction to be applied during open loop.
And just as I'm sure Ford software does not allow "learn" during all facets of closed loop, there are instances when the system may be closed loop, without enabling the long term correction. So learning only happens when the engine is in "normal" operation. ( specific sensor inputs must be within a window to allow full learning!)
Does your software have a similar function?
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Road Master
Joined: Apr 2010
Posts: 795
Likes: 1
Do you know any facts about the adaptive fuel control feature, where the ECU carries over what it learns in closed loop operation to open loop mode? Does this have any affect on the numbers you posted? What is the comparative significance of the different fuels you may get today from tank to tank. Including the various ethanol concentrations, and that gas evaporating faster than ethanol which makes tanks that have been setting for awhile (so called slow stations) have a different concentration... and how that may effect heat build up and wear and tear. How does this correlate with the fact that the HD motor will run at an AFR of 15 all day without complaint, a bit more wear and tear perhaps... but maybe a story for another day?
Seems to be so much to worry about, between HD lawyer speak and VEs, that I better keep the bike parked in the garage, or set it up in the living room as a work of art...
Seems to be so much to worry about, between HD lawyer speak and VEs, that I better keep the bike parked in the garage, or set it up in the living room as a work of art...
Road Warrior
Joined: Apr 2010
Posts: 1,739
Likes: 10
From: Suffolk, England
So, a Xied does a one-off shift of the closed-loop AFR to richer, about 0.5:1 or so, which is good for reducing temp at idle and cruising speed but it does little or nothing for performance, which for many of us is kinda the point of doing a stage-1.
Tourer
Joined: May 2010
Posts: 348
Likes: 5
From: The mitten state
Foxster,Where the SERT software changes the CLB ( closed loop bias) the XiED modifies the O2 sensor signal! It sends an incorrect voltage!
And while the "affect" may be similar to "just changing the CLB", it's impact on fuel control function and more importantly, Diagnostics, are not the same! Where the SERT modifies the actual ECM CLB value, closed loop still functions as designed. The "incorrect" O2 value can and does impact and set diagnostic codes, and the signal for fuel control is affected! Fuel control being the actual way in which the pulse width is switched to maintain Stoich ( or biased A/F ratio).
And while the "affect" may be similar to "just changing the CLB", it's impact on fuel control function and more importantly, Diagnostics, are not the same! Where the SERT modifies the actual ECM CLB value, closed loop still functions as designed. The "incorrect" O2 value can and does impact and set diagnostic codes, and the signal for fuel control is affected! Fuel control being the actual way in which the pulse width is switched to maintain Stoich ( or biased A/F ratio).
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