• Team SLG

How to Data-Log from an E46

I get asked a lot how to data log from the MS4x ECU's, and figured why not document it?!

So the first thing you need to properly data-log is a quality wide-band oxygen sensor and gauge. The oxygen sensor allows you or the tuner to see exactly the mixture of air to fuel that is in the exhaust. This tells you whether the engine is running rich or lean, which is very important not only for performance, but for engine safety as you change how it runs via the tune. This isn't needed for off-the-shelf tunes, but is a must for anything with forced induction or running other large mods. We at SLG recommend AEM gauges and sensors. They have always treated us well and are often the industry standard.


The next thing you need is RomRaider software. Download it from :

The Romraider Logger is the program that will speak to the ECU to record engine information, as well as overlay air/fuel mixture data. For RomRaider to speak the ecu's "language", it needs to reference a definitions file. This file "decodes" the engine information into parameters we can pick and choose to monitor for engine tuning.

You can find the definitions file here:

In RomRaider, click settings and select "Logger Definition Location" and select the file you downloaded above.

While you are doing this, also create a "logs" folder on your desktop, and set it as your output location for the data logs recorded. All the data logs you take will be saved here.

To connect from RomRaider to the car, use a silver INPA K+DCAN cable, such as :

Sometimes, fiddling with drivers is needed, but hopefully you get lucky and the cable works right away!


Ok, so now you have your wide-band gauge installed, your computer has RomRaider running, and your cable is ready to go. The only thing left is to get the information from the wide-band gauge to the laptop.

To do this, you need to take the serial output wire, along with a ground, and attach it to a "serial port" (db-9 connector). Then you use a "serial port" (db-9) to USB converter to plug it into the laptop at the same time as the INPA cable.

So take the leads highlighted and separate them into an area you have connector access:

Then wire the two wires into a serial connector like this :

Please note the male/female side and how it affects wire locations*

Now, use a cable like this to connect to the laptop:


Holy shit- your finally close.

So now, do the following. This software can be finicky.

1) Start car & plug in the INPA cable

2) Plug INPA cable into the laptop

3) Open RomRaider and connect to vehicle

4)Select the parameters you want to record- make sure they're moving around a bit

5) Plug the serial connector into the usb adapter, and then into the laptop

6) Select "Plugins", then select AEM UEGO 9600 (depends what you bought).

7) Select the COM Port the AEM is connected to. It is usually 6 for me. You can check yours via "Device Manager" on your windows laptop.

8) Go log!

PS- This is the best way to log and see your gauges on RomRaider -