Trying to chase down some minor issues and i changed my poorly installed and malfunctioning LC-1 wideband to an AEM wideband. My tuner prefers the AEM so I wanted to go with the one he was used to for easier troubleshooting.

Are there any changes that need to be made to accommodate the AEM? It looks like they both output 0-5v, but I want to be sure before i drive it. I started the car up with the AEM it ran fine and the AEM is working.

Still learning TunerStudio and the plethora of settings in it can be overwhelming.

 

Tools-> Unlock calibrations -> Calibrate AFR Table -> EGO sensor drop down -> AEM x-series.

If that's what you have. Then burn to your ecu and lock the calibrations.

 

Thank you!!!

 

No prob. I'm a megasquirt noob too, so it's nice to actually know something hahhaha.

 

make sure it you pick something from the dropdown it actually matches the published values of your controller.

the "x-series" is:
1v = 9.7:1 AFR
4v = 18.7 AFR

most AEM gauges (like the 4110) use:
0v = 10AFR
4.25 = 18.5 AFR

 

I think the menu has 2 options for AEM accounting for that. I didn't double check the values (will do that now), but I know there are two AEM options.

 

yeah and neither of the two AEM options match the published values...

 

Yup. Realized that when I checked things after reading this thread. Do you recommend just inputting it manually? Ms reports values that are 0.3 or so within my gauge.

 

The options I see in TS are:

AEM Linear AEM-30-42xx
AEM 30-2310, 30-4900, X-Series

I have a 30-4110 UEGO.
From the manual:
0.0v -> 10 afr
4.25v -> 18.5 afr

Now I'm confused which I should be using. I picked the first one. The gauge is reading within about 0.1 of TS.

I may just input manually to be sure I have the correct values.

 

Brain, where are you getting the numbers from?

I just looked up the manual here: http://www.aemelectronics.com/files/...ns/30-0300.pdf

It lists:
0.5v = 8.5
4.5v = 18.00

In the section in the manual titled 0-5 analog output.

 

that's exactly my point...

 

I was wondering where the numbers in post 5 came from since the x-series numbers don't match what I saw in my x series manual!

 

You can always just do a custom linear setup based off your specific gauge.

The 1v was right. 4v wasn't. I think he was quoting the TS values, not the real values. Which are wrong

 

from the "x-series" selection in TS.

 

Ah, gotcha. Sorry, I thought you were quoting that the values you were saying were the right ones. Apologies.

 

Is there any reason to start at 1v vs 0.5V since the values are provided? Or does this really not make a difference since it's linear so it calculates it all anyway? I was just wondering if 0.5V was under the MS' detection threshold or something.

In any event, I just corrected my settings on TS!

 

Its linear. No different.

 

With the values from AEMs chart, I put in:
1V : 9.69
4V : 16.81

Things have still been a bit off and so I'm trying to figure out how to calibrate it. Are any of those values actually fixed? Ie is 4.5 always going to be 18 even if the rest are off, same with .5 and 8.5.

I'm asking because I had to change my 1V value to 1.4V to get idle afrs right, but I think they're off elsewhere. So I'm wondering if I'm better off using one or both of the mostly fixed points and taking it from there. I might swap in the 0.5V : 8.5 value to start with and adjust the voltage there to see what works. Ie adjust voltage up if TS is showing a lower AFR or down if its showing a higher AFR. Or do I have that backwards.

Would that throw off the rest of the values? Is there any way to actually calibrate it other than having AEM test it? I should have asked for that when it was getting warrantied.

And I'll obviously have to redo all the fueling etc one this happens too right? My AEM was reading a bunch leaner all else equal yesterday. So much so that I backed off any time I started getting close to boost because the numbers were making me nervous.

Thanks for the help!
​
Is the best course of action to pick values for the range of those most useful to tuning and go from there? I.e. AFR's between 10 and 17 are probably most useful. So it makes sense to use 1V to 4.5V ( AFR 8.5 and 18 respectively). Now if only I could get the numbers to line up a bit better...

AEM also gives this formula for AFR: (2.3750 * Volts) + 7.3125
So I could also look at my idle on the wideband, pick the lowest and highest AFRs and the corresponding voltage for TS, then adjust the voltage for both of them till the ranges even out. I could use the formula to calculate the new intercept or just leave it as is and let TS extrapolate the line based on two numbers which are ~2 units away from each other (14-16 for AFR). That seems a bit odd to me in terms of setting up a curve with two values so close to each other, but it is linear so...

 

Any updates on this?

 

What's up six? What exactly are you having an issue with?