Lately i have some issues with a stroker engine. While above 80 Kpa it accelerates very nice on the lower sites where the VE is very low (to have an EGO COrr of 97%) compared to the higher sites it needs very long accel duration to get it running and it is still not very good. It accelerates a but and then gets too lean so the lambda rises fast.


While wainting for the EGT chips i was wondering if i should chenge the resistor to use instead of the stock IAT the 1.8T IAT sensor.



EGT problems 0 to 1125 Celsius and again 0 changing every second on VEMS. The sensor is brand new and came in yesterday. Where is the problem? Can it be the controller inside VEMS?


-If i wanna change the AD597 do i need something special or i simply replace it like every SMD chip?

It was the mcp3208


Do we have any MSQ file for the AAN or ADU with Plug n Play VEMS for the 1.1.44alpha firmware. I used the 16x14.

I upgraded to it and now the car doesnt start and i think it has to do with ignition, or other settings, since the files i had where from the 1.1.27beta version.

1.1.44 is not released. If you need some recent feature, 1.1.50 (also not released yet) is a better choice.


Did someone managed to listen and use the stock Knock sensors with VEMS? If yes pleeeeaaaaase help!

Hallo, i was amazed as i saw today that there is a PNP Motronic VEMS.

The question is now how PNP is it and what must i change.

I am not very electronically inclined so my questions are dumb:

I plug the VEMS PNP-Motronic to the harness, istall and connect and verify and calibrate the Wide band and the EGT. Is the car now ready for the Tune?

The VEMS comes out of the box with support for the Ignition, injection and Boost control without further mod to the Sensors or the cables of the Car?

Is it possible to find for starters a full runing program for the ADU engine, and from that point modify it further?

Hi, i am thinking of Using the VEMS v3.x on my currently Stock Audi RS2. It has from the Factory an I5 2.2. liter Turbocharged engine (Engine Code-ADU). The stock ECU system is a Bosch Motronic. For the future i am preparing a strong bottom end and big turbo.

The car is an everyday car and want it to have a cultivated ride (when i am cruising with it or in the City). I want the Climate Control (Air Condition), Auto Check (it has also Trip Computer but i think it will not work with the VEMS).

I would like to make the convertion this way so i must only change the less possible stuff to run on Vems (and also easy to go back to the Motronic system if the car will be sold).

I connected VEMS and tried to connect it to the PC.

The connection is Succesful but i become a Message that the tabes between controller and MT doesnt match.

I Choose 16X14 and it says the Controller has 12x12. I made a FirmwareUpdate? to 16x14 but i still become the same message.

If you have pinout for ADU, we can check if the cyl1 <=> 3 ignition is swapped, so we can hint h[2]= ... change if necessary.

MAT sensor

With bad table chosen at firmware upgrade, the MAT reading will be almost constant, and if it changes at all, it decrease with rising MAT.


It started with Marcels file. Very nice. Still no EGT and WB installed. Very happy!!!


I installed the cables for the Lambda and EGT. The 12V connection for the WB comes not through VEMS but separate doesnt it?

I would also like to know about the WBO2 Calibration Constant. Should i measure it or is it mesured from the factory?

The sensor must be I free air and you should see the number near 20,9 in the lcd display if not you can adjust the Calibration Constant in Megatune.

More info here:


Done some more today. I am seeing the target

AFR at idle but not everywhere else. I also made a Log.

Here is some throttle while standing and the other one my first log while driving. Also the MT File i done it

OK, done some more and i am very pleased with the Results. Car runs fine with this basic tune. I have tryed to controll boost with VEMS but i somehow cant get it, till now!

So i start:

1. It is set to MAP Target but i am going to run it at Boost Target (page was down so i couldnt read about boost settings).

2. Boost is set to 200 kpa but it somehow goes till 240. Right at 240 kpa it takes fuel off - must search why i cant see any that can cause this but maybe i am blind.

3. Must see that somehow i get the knock to work. Dont even know if my channels are correct.


So after running with VEMS and daily use some other issues that i dint solve yet are:

1. After crank up the RPM stay for several seconds high and then it starts going from 1000-1500 RPM so as if i the throttle kick and let and then again. After ca. 30 seconds is it away and idles very nice.

-Do you think i should do the diode install?

Here is the start-up


2. I cant set the boost control up correct. I tryed and set the boost control so now i dont get Fuel cut because on the Inj PW and noticed that i get the Boost i want (almost) but it is not stable. I set it to 1 bar and i get 1.1 then goes down to 0.85-0.9 then again to 1.1 then again down ect.

This is the RPM vs Boost vs TPS log:

3490 167.0 99

3550 173.8 99

3605 181.0 99

3669 188.5 99

3733 197.8 99

3797 206.5 99

3870 214.5 99

3926 201.0 99

3939 188.0 99

4092 192.0 99

4115 202.8 99

4146 212.5 99

4297 212.8 99

4249 196.5 99

4338 184.5 99

4421 185.0 99

4447 197.8 99

4587 211.3 99

4622 204.0 99

4618 189.8 85

4559 162.0 5


i have logs for everything. But mcd-mct for nowthing ? ;-)

The boostcontrol is usually almost a PD-controller.


D=... hard to tell (start with decimal 20)

The I value can be close to 0. Usually there is no time for the I to act in gear 1 and gear2.

As a result, there might be a systematic error (eg. you set 190 kPa but get 210 kPa, this also depends on the boost valve reference position: 1/5, (start with this: 2/5), 3/5, 4/5 (you will get highest actual boost with 4/5, likely significantly above target).

Still have the boost fluctuation problems with the N75 control and i am not so pleased with it yet.

I just realized what crap i writed about the overrun Fuelcut and resume. I was not thinking.

Today i installed the Diode and set the boost settings as mentioned above. Warm car startup is very nice and the boost very smooth. Thank you very much for your help. I am very happy with the Results.

The next step would be to set the knock sensing better than i have now.

Thanks again

Anybody knows why now and then i have this problem during idle. It seems that the Idle valve doesnt respond so fast. It gets worse with AC.

Can it be that my Idle valve is faulty? It happens occasionaly.

This is my file at the moment:

Please comment or suggest changes for EGO, VE-Autotune, Idle ect. Whatever you think is wrong please comment. I also need to tune the Spark table further and a bit the lambda.


Today i did a 200 km Trip and have noticed that when crousing and going at about 100 KPA then the EGT goes till 750 Celcious. The EGT sensor is right after the turbo. Is it ok or should i change something?

Knock sensing

Can someone help with the Knock control? Does it read both sensors? What settings should i have? Should do it with the Terminal or with MT?

See knock_chan (for channel 0 and channel1) on GenBoard/UnderDevelopment/FirmwareChanges

You can also check KnockListener during tuning.

What are you use for the MAT sensor? I used ptc_260_425 but it doesnt move so fast with temperature changes and it doesnt seem so "sensitive". Must it be like this or is the file not soooo good?

Should i go with a newer Firmware or is the 1.1.27b the best for Auditrigger?


I have been running closed loop under all conditions, also under wot, but it seems to not being able to maintain lambda 1 at idle, were it will swing from 0.97-1.07 or so,

is i turn ego off it will be stable.

I made the VE-Table as accurate as i can but when on idle and the fan kicks in it takes 20 seconds or so for the idle to be somehow stable. When the fan stops i get the same. When the AC is on the same ect.

It is stable only at the conditions where i tuned it (i.e. warm engine and AC off, and big fan off) when something changes it starts to jump here and there.


Managed to run the 16x14 FW and map i made. Problem: idle RPM stays very low when AC is ON.

Is there anything to do with this on the 1.1.27 FW Version?


Or must i wait for the newer ones with the map switching ect?

map switching should not be needed for AC, although 2 different sets of iac_ref_pos[] make it easier. The same effect as a 100..510 Ohm resistor from iac pin switched to GND when AC is active (AC relay input, if active low): to add some current to iac to open it more when needed.

The VBatt compensation in 1.1.3x will help for sure. The vbatt tends to drop with RPM around 900 RPM (mostly because of the Bosch alternator), which cries for this vbatt compensation, true

Do you have logs with AC and without AC ? Just make sure to number logs the same way as the mcd / mct dumps if you change the config in the meantime (as is likely)





Thanks a lot