After checking AutoMeters site I do not see an output with a 0-4v or 0-5v signal. You need this type of output from your gauge to do this mod. I would check with AutoMeter directly to see if there is a way to get this output from your gauge.

 

just to reiterate, ams did whatever was listed in the first post and now my autometer is getting read by evoscan through tactrix! i love it. changed the formula since my low and high readings are 10 and 16 respectively. matches my autometer boost gauge so i am happy. they'll be taking care of my CEL through tephramod or whatever as well.

in short: post #1 method for logging autometer works - thanks again!

 

hi guys,
this formula 10+(16-10)*x/204 doesnt read right on evoscan properly for me i`m afraid the autometer is spliced into the rear o2 loom and reads fine through the ecu but to get it to read 14.7 at idle/cruising i have to use 10+(16-10)*x/185. this puts the afr at about 10.2ish under full load when it should be reading 11.4 (confirmed).

also if i negative back to the ecu through the loop and not to chassis ground i get a low voltage cel, i assume this is because the ecu is expecting 5 volts?

am i doing something wrong? as i read on here it should work perfectly.

thank you.

 

Try this, just figured it out today for my AEM uego which is a 0-5V signal.
10+1.960784(.01960784*x)
I'm almost positive that should work for you as well.

 

the autometer is 0-4v signal though?

 

so try this one and let me know if it works, should be pretty close if not right on.
10+2.35925299*(0.01960784*x)

 

umm, a log of about 144 on idle, thats 144, not 14.4, lol

i`ve also tried this one (X*((0.000033118*X)+0.0403455)+8, same result, a afr of about 147, so i put /10 on the end to try to divide the reading by a factor of 10, no change

i shall persevere

 

Log the oxygen sensor #2 (voltage) with evo scan. Should read about 1.99 or 2 volts when at 14.7 on the gage. If so, turn the car off to stop the engine and then back to the on/acc so that your gage will come on and continue to read different voltages as the meter slowly maxes out to lean. Write a few vales down. And post them here for me. Since it's a 0-4 v gage, I'm assuming the voltage at 14.7 should read about 2 volts. Post them up here for me and I'll get you an equation. Should look like this
14.7=1.99 V
15.4=2.4
16.2=3.0
Something along these lines.

 

yeah so far the only formula that reads the same as the gauge face at idle is 10+(16-10)*x/170/180 ish got me beat which according to merlin, my resident electrical engineer is similar to yours is just a a longer equation.

this /170 has no correlation with the original equation on this thread for a 0-4v spread, that final number was 204 which is 255 divided by 5 and multiplied by 4, ie 204

should work, but not

170+ish gives me the gauge face readings which fluctuates from about 14.8 to 15.

so, meh, u want me to send u a .csv but failing miracles it wont help.

it isnt that easy, theres an offset somewhere, maybe in the ecu.

 

I think you may be putting the equations in wrong somehow or maybe just a typo. the figure "x" should only range from 1 to 255. which in any of those equations, wouldnt give a reading of 140 something. You should make sure that evoscan is making the right request which is 3C for the rear O2. And I think that also changes with the market of the car USDM vs AUDM or JDM. Just an idea to check.

 

From what I've read, all the uegos use a linear equation to covert voltage to thier readings. So with that in mind, my last equation for a 0-4V gage should've been

10+2.35925299(0.01960784*x)

and a 0-5V should be

10+1.960784(.01960784*x)

The numbers you were getting are due to something else with in the car being setup wrong or that EVOSCAN is making a wrong request. I know for USDM that the request for rear O2 is 3C. So maybe its just as simple as a different request for your market model.

 

thanks for the reply, i`ll try those out, and yeah, the request is 3C.

from autometer instruction .pdf

 

If that doesn't work for you, then make a new request on evoscan for the rear o2 (3C)and just set the equation to "x" and see what the ecu signal is actually giving you. It's "should be" a number between 1 and 255. Also, you should be running the tephra mod so you don't get a CEL and you can't use the rear O2 patch with the car set up this way. Hope this gets us in the right direction