Thread: AEM UEGO wideband logging with tunerpro v5 HELP! have tunercode

I only have a basic board calum ecu guys. So I am using my front o2 to input the signal! Now here is were I am having trouble. The tunercode adx and help documentation says it accepts a 0-5v signal. Now it already has the formula in place with the tunercode ADX. The formula says to setup the AEM UEGO in the 1-2v format. BUT other information on this site and nismotronic say to just half the values (/2) and your good to go.

My AFR display shows up as 19-low 20's AFR lol...

BUT under o2 voltage it shows the CORRECTED HALF VALUES, seems that's its not transferring the conversion over to the AFR display. I can't get it to work right in Nismotronic or Tunerpro

Under O2 input should it be x/50 instead of x/400 ?

I have tried both formula's I found for the AEM under wideband with no luck.

Do I need the same formula under o2 as wideband AFR or just wideband AFR and leave the o2 at x/400?

Or the AEM UGEO only works with tunerpro/nismotronic in the 1-2v mode?

With the AEM UGEO in 1-2V mode (switch at P2) AFR = (RAW O2 voltage)/40 or (actual O2 voltage)x10.
Full scale voltage is 2.5V and with 10bit A2D converter this gives approx. 1000/2.5=400 counts/V so a RAW O2 voltage count of 560 gives 560/40 = 14.0 AFR and an actual O2 voltage of 560/400=1.4V and 1.4x10 = 14.0 AFR.

Dave

Wow that's a bit overwhelming lol.

Let's start off with what mode should I be in 0-5v or 1-2v mode??? Everything on the forum, tunercode and nemu help says to use the 0-5v analog wire and divide by 2 if logging wideband through o2 input. If wired through adx/serial direct, no conversion needed.

In the tunercode you provided me, it has the formula of:
(AEM 1-2v wideband x*0.025)

But here on the forum ive found this formula????? (2*x/50)+10 for the 0-5v UEGO. Are these just two different formula's for either method. So either should work. Im sure the 0-5v mode is best?


So are we now saying the UEGO must be in the 1-2v mode (p2) to show proper air fuel? and that it will not work in 0-5v mode?

Can we go over the 2 areas of concern to get this working. Which is the correct formula's for each 02 and a/f under values in the adx editor?

You gave me:

o2= x/400
a/f= x*0.025

I got the wideband to work in tunerpro using the o2 input for wideband only by using P2 mode on the AEM UEGO

values ended up to be
o2 (x/400)
a/f wideband (x*.0210) instead off your supplied (x.0250)

Seems ok now.

Man, I've been working off-and-on all day to a response for you, but glad to hear you have it working. BTW: (voltage x 0.025) is the same as (voltage/40). The (voltage x 0.025) is a reasonable ball park to start from. Everyone has a slightly different voltage offset due to grounding, wiring, analog-to-digital conversion (A2D) differences, etc., so by all means, adjust the conversion so your logged readings match the gauge reading, or some other reliable AFR reading (like a sniffer on a dyno). I adjusted mine to match my AEM UEGO gauge reading.

Dave

I should also say that some wide bands have only a 0-5V output and are not programmable like the AEM. For those, a divide-by-2 voltage divider is required because the stock O2 sensor input range is 0-2.5V.

Dave

I would have preferred to leave in it P0 mode 0-5v. Would this be more accurate than the p2 1-2v mode?

I could only get it work in the p2 mode. I tried a ton of different conversions too

I fully understand 0-5v needs to be divided by 2 BUT where does this go? under values for O2? and this forumula under a/f (2*x/50)+10 ?

I'm just glad its working now btw I had to go this route because my old Nismotronic ST lol would not connect to direct analog logging with the CORRECT com port.

In Nismotronic I got it working again by using P2 mode and values of 0=7 and 5=17 I think

You have to make a 2 resistor divide-by-2 voltage divider like the circuit shown in the link: voltage divider
This divides the 0-5V coming from the wide band by 2 so it is 0-2.5V at the ECU.

Oh well that explains everything! lol I totally missed that. I thought that you just put "/2" in the formula some how. That's why in Nismotronic I couldn't find a place to put in "/2" hahaha.

Can I use any 2 "same" resistors? Appears so by playing with that link. I can also tie the 2 pieces of wire together at in Volt in and Volt Out? I will try this. You should have all this in the documentation

I would use at least 10k ohm (that's 10000 ohm) resistors to limit the current draw from the wide band.

It is in the documentation in LoggingReference.doc:
"O2 Voltage
Voltage reading from O2 sensor. The O2 sensor voltage input to the ECU has a range of 0-2.5V. To log 0-5V output from a wide band sensor, use a divide by 2 voltage divider to scale the 0-5V down to 0-2.5V and clear the Enable Closed Loop O2 Analysis flag."

As far as converting O2 voltage to AFR, that is wide band controller dependent so isn't documented for all possible wide bands.

Dave