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). 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 , 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 , 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

[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 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.