Setting up AIM MXL Pista dash to work with AEM EMS

[turbogate]

Hey Guys, this was originally a question, but since I figured it out, I thought it would be a good idea to edit this post into a small write-up.

Here's how to create the USB cable if you don’t have it. If you buy your dash brand new, it will come with it. You need it to connect to your Strada or Pista dash to upload your set up, and download logs. This cable retails for $65, but with radio shack and a computer store and some basic soldering skills it can cost you ~$12 (that was my first shot at soldering and I nailed it).:icon_bigg The audio type connector I used from RadioShack was part# 274-244 $3. Be sure when you are done soldering to use a multimeter to make sure there are no shortcuts. You only need to solder the wires shown on the picture. Cut and cover the red USB wire and also cut the main cable shield.

This is the standard wire coloring for USB cables
GNB is the black wire
D+ is the green wire
D- is the white wire

The red wire is NOT used.

Here's my pride and joy

The Serial adapter is also easy to make thanks to RadioShack. I used a Crimp type D-Sub connector Part# 276-1427 from RadioShack. All you have to do is use the picture below for which wires to use. You only need 2 wires. The serial ground wire can be shared with the same MXL GND wire.

Now once you are done, and everything is configured properly. (See user manual for AIM MXL and Race studio, it's pretty self explanatory) All you have to do is connect to your AEM EMS with a laptop. Go to Set-up>advanced setup>Telemetry>Telemetry wizard. Double click on AEM Serial Datastream and click OK. Now you may loose connection to your AEM for a few seconds because the AEM is now in Telemetry mode. All you need to do is cycle the power (turn key off-on) so you can reconnect to your ECU. Once there, go back to Set-up>advanced setup>Telemetry>Telemetry set-up and change the Parity setting from Ignore to none (that was my issue for my original issue) then click OK, once again your laptop will loose connection to the ecu. Close out AEM pro kill the ignition to avoid connecting the serial cable to the dash while it's on, connect your AIM serial cable to the AEM serial cable and turn back on. The Dash should now be streaming the AEM selected data.

Enjoy

ps: Hopefully an expert like John Reed will chime in and correct me if there are mistakes in the write-up or unnecessary steps, so I can adjust the write up

 

[turbogate]

One thing I wanted to add, now that I've been running the dash on my car for a while. While the AIM dash reads all the expected/supported parameters from the AEM. I just read a post from John Reed that the AFR signal displays as Lambda, not AFR. It will display data if you select AFR format in the software, but it does not compare visually(format wise) to my AEM UEGO. It looks like it ignores the AFR format and still displays lambda. Also Boost/engine load also does not match my boost gauge even though I adjusted the parameters in the AIM MXL manager software. I does not show vacuum, it is always displaying a + number. I also read that an extra wire needs to be run, but I don't know yet which one. Hopefully he will chime in. Besides these 2 parameters, everything else runs as advertised. speed-rpm-gear-various temps etc. I'm also trying to figure out if it's possible to bring in the knock voltage as a parameter, since it's read as voltage(I think) (using ACDR 11-16?)

 

[figgie]

quick question

the boost parameter.. What are you displaying? Kpa? PSI? mm/HG? The thing about PSI is that is does not have a "negative" per say. That is why most guages read PSI for positive boost and then go in mm/Hg when reading a vacuum.

As for your Lambda reading. What are you using for the Channel? (Bosch, NTK or AiM Lambda LCU-One or even a General 0v-5v input?

 

[turbogate]

quick question

the boost parameter.. What are you displaying? Kpa? PSI? mm/HG? The thing about PSI is that is does not have a "negative" per say. That is why most guages read PSI for positive boost and then go in mm/Hg when reading a vacuum.

As for your Lambda reading. What are you using for the Channel? (Bosch, NTK or AiM Lambda LCU-One or even a General 0v-5v input?

Thanks for the reply figgie:icon_bigg , ok where do I start?

My boost parameter or MAP as load is being displayed in the AEM log/parameters in psi. It's actually not boost per say, but engine load which is slightly different if I’m not mistaken to actual map boost/load (I think) its pretty close (I'm sure you know that also), I believe the AIM only accepts Engine load as valid parameter. The AIM dash gets the engine load signal from the AEM which is feed by an AEM 3.5 map sensor. Ironically, if I make a run and log it internally or with the AEM logging software, it will display the data correctly in the AEM log (vacuum and boost). I think it has something to do with the way the AIM MXL translates those signals. With the MXL dash, it will display +9 "something" at idle and will go up to like 40-50 of that value when I'm really showing ~17psi on my boost gauge lol. So I have no idea what it's telling me.

As for the AFR reading of the AIM dash, it is also receiving the AFR data from the AEM which the AEM gets it from my AEM UEGO wideband via its 0-5v output. (hope I'm not loosing you, lol) In other words I’m not using any AIM sensor at the moment. Everything is being streamed from the AEM EMS. The AEM outputs the AFR signal in the AFR gasoline format, which was set-up in the AEM unit set-up window. Its just that even though I told the MXL that it is receiving that data as AFR units (via the AIM manager software) it still displays AFRs as a 0.9 instead of 14.7 for example. It may be that the AIM dash only displays AFRs correctly in Lambda. I'm going to have to learn how to read lambda. You would think that by adjusting these settings, the AIM would then know what to do, but changing these values made no difference. See picture below. (That's the AIM MXL software) the values I highlighted are min a max values that can be typed in.

 

[figgie]

Thanks for the reply figgie:icon_bigg , ok where do I start?

My boost parameter or MAP as load is being displayed in the AEM log/parameters in psi. It's actually not boost per say, but engine load which is slightly different if I’m not mistaken to actual map boost/load (I think) its pretty close (I'm sure you know that also), I believe the AIM only accepts Engine load as valid parameter. The AIM dash gets the engine load signal from the AEM which is feed by an AEM 3.5 map sensor. Ironically, if I make a run and log it internally or with the AEM logging software, it will display the data correctly in the AEM log (vacuum and boost). I think it has something to do with the way the AIM MXL translates those signals. With the MXL dash, it will display +9 "something" at idle and will go up to like 40-50 of that value when I'm really showing ~17psi on my boost gauge lol. So I have no idea what it's telling me.

As for the AFR reading of the AIM dash, it is also receiving the AFR data from the AEM which the AEM gets it from my AEM UEGO wideband via its 0-5v output. (hope I'm not loosing you, lol) In other words I’m not using any AIM sensor at the moment. Everything is being streamed from the AEM EMS. The AEM outputs the AFR signal in the AFR gasoline format, which was set-up in the AEM unit set-up window. Its just that even though I told the MXL that it is receiving that data as AFR units (via the AIM manager software) it still displays AFRs as a 0.9 instead of 14.7 for example. It may be that the AIM dash only displays AFRs correctly in Lambda. I'm going to have to learn how to read lambda. You would think that by adjusting these settings, the AIM would then know what to do, but changing these values made no difference. See picture below. (That's the AIM MXL software) the values I highlighted are min a max values that can be typed in.

Well I think I see your issue in the pressure section.

Remember that 14.97 psi is 1 atmposphere of pressure at sea level. The issue though is that PSI is not an absolute value but usually used as a gauge value which means that zero on the gauge is not really zero but instead is the 1 Atmosphere/100 Kpa/1 Bar/14.97 PSIa (Absolute).

What happens when you put the lowest number as Zero and not that negative number?

On the AFR front. I see two channels coming in from the AEM for Lambda. Both from the same lambda sensor (Lamda Sensor). I would disable one on teh AiM side and go from there.

 

[turbogate]

Well I think I see your issue in the pressure section.

Remember that 14.97 psi is 1 atmposphere of pressure at sea level. The issue though is that PSI is not an absolute value but usually used as a gauge value which means that zero on the gauge is not really zero but instead is the 1 Atmosphere/100 Kpa/1 Bar/14.97 PSIa (Absolute).

What happens when you put the lowest number as Zero and not that negative number?

On the AFR front. I see two channels coming in from the AEM for Lambda. Both from the same lambda sensor (Lamda Sensor). I would disable one on teh AiM side and go from there.

I'm the one that changed those values to -14 to ~35 to match the parameter output range that the AEM telemetry claimed to output in that channel. The telemetry option window in the AEM has a table that shows the signal ranges etc that is expected in there respective channels. It was a 0 to something (would have to check the default setting) originally and it was still displaying the same positive range mentioned earlier. I changed it thinking that was why it was displaying only positive numbers since it’s suppose to only display what's coming from the AEM. I saw John Reed mention in his section on the other forum that there's one more wire that can be wired to the AIM that will make it display boost correctly, but I have no idea what it is, hopefully he will chime in. I am wondering if he is talking about also bringing the map sensor signal output to the AIM dash. After all the AIM does have room for 8 more additional sensors.

On the AFR front. The AEM has 2 lambda (pins) inputs. Lambda #1 and #2. Typically, Lambda #1 is where you put the wideband sensor signal and Lambda #2 can be used for the stock O2 sensor, but it's usually not used(my lambda #2 pin is not connected) The screen capture does not show where I unchecked Lambda #2. The "lambda sensor" column you see is just the name column. Probably later today after work, I will choose the lambda setting and see if the display will make sense:icon_bigg

 

[figgie]

well

remember. The sensor reads Absolute pressure (Manifold Absolute Pressure). THE AEM is then translating that to what you see -14.97psig - 0psig - 30 psig. In the end the AEM has to be sending either a voltage signal (0v-5v) or the number it is translating but not both. I read though most of the manuals and saw nothing pertaining to scaling the signal in the AiM.

 

[turbogate]

well

remember. The sensor reads Absolute pressure (Manifold Absolute Pressure). THE AEM is then translating that to what you see -14.97psig - 0psig - 30 psig. In the end the AEM has to be sending either a voltage signal (0v-5v) or the number it is translating but not both. I read though most of the manuals and saw nothing pertaining to scaling the signal in the AiM.

I hear what you are saying. the values you see, -14 - 35psi and so on was just a test to see if it would make a difference as it did not read correctly with the default setting. I will put back the default AEM-load AIM setting to see what the difference is and also try to do a small video to show you what it's displaying as far as boost when it has the default setting. i'll use that opportunity to switch to Lambda output as well.

Thanks

 

[turbogate]

Here's a drive around I did this evening. My boost controller is set at 12psi. With my camera on one hand and my lambda to AFR convertion sheet on the other :biglaugh: I made a couple of small runs to show you what it is displaying. Now for the AFR, I think it's where it should be while displaying Lambda values. For the engine load/boost, I choose bar instead of psi, I put the range values back to default, no more negative values etc, and this is what I got. I'm definitly not boosting 3 bars, lol I may have to go back to AEM pro and change my pressure to bar however.

( I had to downsize the video size, so I lost some quality. You should still be able to see the dash display)

http://www.youtube.com/watch?v=6hYMYZv5UXw

 

[figgie]

Under the AEM.

Under the configure, units option.

What do you have there for Load units and AFR Units?
Do you by chance have the telemetry enabled in the AEM? I was looking at the telemetry portion and this has to be setup for the items you want sent.


Reason I say this is that on the MoTeC and just about every other ECU. The serial port is used as a telemetry and has to be configured in the order that is shown on the AiM to work correctly.

As a matter of fact try this

under Setup > <<advanced setup>> > Telemetry > Telemetry Wizard. Select the AEM Serial DataStream Gauge and if you go back to Setup > <<advanced setup>> > Telemetry > Telemtery Setup. It should be the same as the list from AiM for seting up. Press show info and it should tell you everything it is sending via Serial.

 

[turbogate]

Under the AEM.

Under the configure, units option.

What do you have there for Load units and AFR Units?

It seems like it is sending something else and the AiM is translating it to what you see.

Also under the Race Studio 2. When you created the first entry for your MXL. I assume you selected F/MPH/PSI?

I'm going to check that tomorrow, if i recall correctly, the AEM units setting are still psi for load, and AFR gasoline. Race studio was set-up initially as F/MPH/PSI to match the AEM, but that is what started all of this. So now that I just changed the race studio setting this evening to bar and lambda, I will also change the corresponding units in AEM pro to see what I get, and I will post results tomorrow.

Thanks again

 

[figgie]

I edited my post. So incase you are still up, See the post you quoted

 

[figgie]

any updates?

 

[turbogate]

any updates?

Not yet, there will be plenty by sunday :icon_bigg

 

[figgie]

Well like i said, triple check the telemetry setting as it really does need to be turned on

 

[turbogate]

Ok, weekend is over, I did some adjustments and here's what I got. The AFR reads fine, but in Lambda. First thing I did on saturday was to first make sure the EMS reads the same as my UEGO gauge. This is done by adjusting a value in the O2 gain option. This part is critical if one wants to use logged runs to tune the fuel map. Mine was a little bit off and it would not have helped me confirm that the Dash is transmiting the lambda correctly. I took care of that, and did a couple of runs with the laptop on the passenger seat logging and by comparing(when I could) the gauge to the laptop. After I got them pretty close, I changed the unit to lambda and updated the MXL settings and it is now displaying the lambda pretty good. I believe the AIM Dash can only display AFRs in lambda.

As far as Engine load, the AEM pro software unit settings has no bar display units/option, unless I'm missing something (i'm not good at conversions :icon_bigg) the load unit options are: inHg, kPa, mmHg, Percent, PSI. So until I learn which extra wire I need to connect. I'll just do without that parameter. I did in the process add 2 new parameters, Knock 1 & 2 volts which can be used instead of 2 of the ADCR** parameters that only display voltages anyways. I seems to display them fine.

I will do some more research online to see what extra wire John Reed was talking about in his AIM thread on SF. I have not had the chance to ask him, maybe I should. The only reason I wanted to have those 2 parameters anyways is because of the alarm led feature of the Dash. Could get a general idea of when I'm overboosting etc. But I can survive without it.

 

[figgie]

Bars?

100KPA = 1 Bar

so 300 Kpa = 3 bars.

you never answered if you have the telemetry turned on or off?

The AEM does AFR (even to the fuel like gasoline etc) located in the same screen as the load unit (AFR Unit).

Also you canVERIFY what the AEM is sending by going into the telemetry setup (2nd time I tell ya ) and press a show info. That displays everything that is being transmitted and in what value.

 

[turbogate]

Bars?

100KPA = 1 Bar

so 300 Kpa = 3 bars.

I knew that :sarcasm:, lol you would think that with all the googling I do, I would find that out and save the embarrassment, lol Thanks, I'll try that

you never answered if you have the telemetry turned on or off?

Telemetry is ON, I guess I never answered that question directly, I would not have been able to post that little video if it was off. Nothing would have been transmitted to the AIM dash. As soon as you turn telemetry ON in AEM pro, you actually loose connection to the ECU with the laptop momentarily, then you have to recycle the power, connect the AIM dash to the serial cable, then it starts to transmit.

The AEM does AFR (even to the fuel like gasoline etc) located in the same screen as the load unit (AFR Unit).

I used to have the AFR unit set to AFR Gasoline(that's how I'm used to reading and logging my AFRs), but the AIM dash never displayed it in that format (14.7 etc) I believe it still always tried to display it as lambda(0.80 etc) now I chose the lambda AFR unit, and I think it's dead on now.

Also you canVERIFY what the AEM is sending by going into the telemetry setup (2nd time I tell ya ) and press a show info. That displays everything that is being transmitted and in what value.

I did verify what the AEM was sending since day one with the info screen:icon_bigg that was how I came up with changing/matching the min-max value in the race studio side to that info screen. Now after you mentioned it, I went back there and saw that the AEM was transmitting AFR gasoline values to the dash, so I changed that to lambda and it seems to be more accurate. Also everything is in sync between the AEM pro parameters and Race studio, so the dash is not receiving parameter x when it should be receiving parameter w.

Next, I will select the kpa load unit, and see how the AIM displays it. All I want to be able to do with that parameter is set-up an overload/boost alarm led. So I can set-it to 144 kpa or ~1.44 bar or ~21psi:evil2: I learned that from you, lol. I'll let you know how it went.

PS, if you have the time, this is the thread/post where I read about that extra wire needed to display load/boost in psi, maybe you can interprete it differently than I.
This post

Thanks again for following up.

 

[figgie]

I knew that :sarcasm:, lol you would think that with all the googling I do, I would find that out and save the embarrassment, lol Thanks, I'll try that



Telemetry is ON, I guess I never answered that question directly, I would not have been able to post that little video if it was off. Nothing would have been transmitted to the AIM dash. As soon as you turn telemetry ON in AEM pro, you actually loose connection to the ECU with the laptop momentarily, then you have to recycle the power, connect the AIM dash to the serial cable, then it starts to transmit.


I used to have the AFR unit set to AFR Gasoline(that's how I'm used to reading and logging my AFRs), but the AIM dash never displayed it in that format (14.7 etc) I believe it still always tried to display it as lambda(0.80 etc) now I chose the lambda AFR unit, and I think it's dead on now.



I did verify what the AEM was sending since day one with the info screen:icon_bigg that was how I came up with changing/matching the min-max value in the race studio side to that info screen. Now after you mentioned it, I went back there and saw that the AEM was transmitting AFR gasoline values to the dash, so I changed that to lambda and it seems to be more accurate. Also everything is in sync between the AEM pro parameters and Race studio, so the dash is not receiving parameter x when it should be receiving parameter w.

Next, I will select the kpa load unit, and see how the AIM displays it. All I want to be able to do with that parameter is set-up an overload/boost alarm led. So I can set-it to 144 kpa or ~1.44 bar or ~21psi:evil2: I learned that from you, lol. I'll let you know how it went.

PS, if you have the time, this is the thread/post where I read about that extra wire needed to display load/boost in psi, maybe you can interprete it differently than I.
This post

Thanks again for following up.

good!

so now that you are sending Kpa and the AIM recieves bar. Change the high point setting. 150 bars. I am thinking you will never get that high I would put it at around 3 bars tops

Then if you want to test.

Change the AEM unit to PSI and adjust the AIM to PSI also. See what numbers you get. Though nede to dig into the other wire for PSI. Does not make any sense if it is part of the serial stream.

 

[turbogate]

Though nede to dig into the other wire for PSI. Does not make any sense if it is part of the serial stream.

I'll let you know how it goes later today.

As fas as that extra wire, The AIM has 8 additional analog inputs which can be used for additional sensors etc. I think maybe what he's doing is using the AEM map sensor wire signal into one of those AIM analog inputs, therefore not streaming the engine load thru the serial cable but directly into the Dash, like this you would set-up the AIM like if you had added a pressure sensor.(maybe I'm not even close, lol)