how-to: Log AFR from the LC-1 w/o a serial cable
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EvoM Guru
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From: Tri-Cities, WA // Portland, OR
Evolved Member
Joined: May 2009
Posts: 522
Likes: 2
From: mnt vernon ny
Does anyone know if this can be done with the AEM wideband? Run the blue wire into the ecu and the black wire to ground (those are the 2 wires that go into the serial connector)?
Just curious if there is a solution rather than logging the aem through a diy serial connector?
Basically I am working on tuning a car with a aem wideband and we cant get the serial cable to work - its wired correctly, and the computer is recognizing the usb to serial adapter (dynex) but evoscan just comes up with an error every time......
I am going to try flashing the V5 94170014 patch (he has 94170008 currently and the 14 is supposed to work) on his ecu for the rear O2 sim and thought maybe we can ditch the serial and log the aem through the ecu instead?
Any help would be appreciated!!
Just curious if there is a solution rather than logging the aem through a diy serial connector?
Basically I am working on tuning a car with a aem wideband and we cant get the serial cable to work - its wired correctly, and the computer is recognizing the usb to serial adapter (dynex) but evoscan just comes up with an error every time......
I am going to try flashing the V5 94170014 patch (he has 94170008 currently and the 14 is supposed to work) on his ecu for the rear O2 sim and thought maybe we can ditch the serial and log the aem through the ecu instead?
Any help would be appreciated!!
It is the white according to the manual.....Ignore that post when i made it i didn't have a manual and it was for a friend - he just made the serial connector and logs that way. Someday we may hook up the white into the ecu but for him it works so we left it alone....
Evolving Member
Joined: Dec 2005
Posts: 419
Likes: 0
From: Bristol, England
Hi All
I'm wanting to wire the putput 2 from my LC-1 into pin 75 on the ECU rear o2, but as I have the 260 there is already a wire connected to it to the rear o2 sensor.
As i've removed this and run the patch in the ecu I was going to wire the LC-1 into the connector where the sensor was.
I did a test last night logging the o2 inputs front and rear and when I connected a C size battery (about 1.2v) across the sensor wiring the ecu logged about 1.2V which is what I was hoping a it shows it is reading but the front o2 sensor went from 0.03v something to 0.7v when the battery was connected and then dropped when removed.
Is there a coupling between the front and rear o2 sesnors? looking at the wiring diagrams on pages 90-44 and 90-45 of the manual there is something that connects the grounds but I would have assumed that the input signals are seperate.
Can anyone comment on this? is it because I used the sensor ground, I was going to try a different ground later (after I finish work) to see if that solves the problem as I wanted to use the connector as its very handy where it is.
Thanks
Andy
I'm wanting to wire the putput 2 from my LC-1 into pin 75 on the ECU rear o2, but as I have the 260 there is already a wire connected to it to the rear o2 sensor.
As i've removed this and run the patch in the ecu I was going to wire the LC-1 into the connector where the sensor was.
I did a test last night logging the o2 inputs front and rear and when I connected a C size battery (about 1.2v) across the sensor wiring the ecu logged about 1.2V which is what I was hoping a it shows it is reading but the front o2 sensor went from 0.03v something to 0.7v when the battery was connected and then dropped when removed.
Is there a coupling between the front and rear o2 sesnors? looking at the wiring diagrams on pages 90-44 and 90-45 of the manual there is something that connects the grounds but I would have assumed that the input signals are seperate.
Can anyone comment on this? is it because I used the sensor ground, I was going to try a different ground later (after I finish work) to see if that solves the problem as I wanted to use the connector as its very handy where it is.
Thanks
Andy
Evolved Member
Joined: May 2009
Posts: 522
Likes: 2
From: mnt vernon ny
ok ive been looking at the gauge and the logs and the gauge round to the 1/10th, and the anolog doesnt. also the shield *seems* to work. im picking up a usb to serial converter today so im goin to see how well the shield works. does the evos rear o2 have a shield around it as well? my rear and front o2 did.
That's a range of 6.5@0V to 21.5@5V, given by the equation V*3 + 6.5 = AFR. (Go back to high school algebra: remember multi-value equations? Given "0.5x + y = 8" and "4.5x + y = 20", solve for x and y. x ends up being 3, y is 6.5)
So, we want to rescale that to a range of 0 to 255, which is how the ECU reads voltage. That gives us an EvoScan-style equation like:
So, we want to rescale that to a range of 0 to 255, which is how the ECU reads voltage. That gives us an EvoScan-style equation like:
(21.5-6.5)/255*x + 6.5
Or, with less on-the-fly calculation going on:0.05882353*x+6.5
Someone want to double-check my math?
Last edited by logic; Feb 22, 2010 at 11:23 AM. Reason: Fixed typo in pre-calculated version, thanks gnz!
Evolving Member
Joined: Dec 2005
Posts: 419
Likes: 0
From: Bristol, England
Hi All
I'm wanting to wire the putput 2 from my LC-1 into pin 75 on the ECU rear o2, but as I have the 260 there is already a wire connected to it to the rear o2 sensor.
As i've removed this and run the patch in the ecu I was going to wire the LC-1 into the connector where the sensor was.
I did a test last night logging the o2 inputs front and rear and when I connected a C size battery (about 1.2v) across the sensor wiring the ecu logged about 1.2V which is what I was hoping a it shows it is reading but the front o2 sensor went from 0.03v something to 0.7v when the battery was connected and then dropped when removed.
Is there a coupling between the front and rear o2 sesnors? looking at the wiring diagrams on pages 90-44 and 90-45 of the manual there is something that connects the grounds but I would have assumed that the input signals are seperate.
Can anyone comment on this? is it because I used the sensor ground, I was going to try a different ground later (after I finish work) to see if that solves the problem as I wanted to use the connector as its very handy where it is.
Thanks
Andy
I'm wanting to wire the putput 2 from my LC-1 into pin 75 on the ECU rear o2, but as I have the 260 there is already a wire connected to it to the rear o2 sensor.
As i've removed this and run the patch in the ecu I was going to wire the LC-1 into the connector where the sensor was.
I did a test last night logging the o2 inputs front and rear and when I connected a C size battery (about 1.2v) across the sensor wiring the ecu logged about 1.2V which is what I was hoping a it shows it is reading but the front o2 sensor went from 0.03v something to 0.7v when the battery was connected and then dropped when removed.
Is there a coupling between the front and rear o2 sesnors? looking at the wiring diagrams on pages 90-44 and 90-45 of the manual there is something that connects the grounds but I would have assumed that the input signals are seperate.
Can anyone comment on this? is it because I used the sensor ground, I was going to try a different ground later (after I finish work) to see if that solves the problem as I wanted to use the connector as its very handy where it is.
Thanks
Andy
That's a range of 6.5@0V to 21.5@5V, given by the equation V*3 + 6.5 = AFR. (Go back to high school algebra: remember multi-value equations? Given "0.5x + y = 8" and "4.5x + y = 20", solve for x and y. x ends up being 3, y is 6.5)
So, we want to rescale that to a range of 0 to 255, which is how the ECU reads voltage. That gives us an EvoScan-style equation like:
So, we want to rescale that to a range of 0 to 255, which is how the ECU reads voltage. That gives us an EvoScan-style equation like:
(21.5-6.5)/255*x + 6.5
Or, with less on-the-fly calculation going on:0.5882353*x+6.5
Someone want to double-check my math?
Well i just took a video of the laptop and HKS Gauge side by side. The formula is in the ballpark but is not spot on with the gauge. Charting it out in excel, they both go rich and lean at the same time, but the difference in afr values is .2-.6 with the Evoscan reading lower.
Last edited by qnz; Feb 21, 2010 at 01:04 PM.