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How to: Datalogging Wideband in Romraider

Every person running Romraider for datalogging will need this!

this DIY will make your and my life easier as remote ecu tuning is something that can not be done in Blind.

When we are doing custom remote ecu tuning we require proper data from customer for analisys in order to precisely adjust maps to achieve best results.

keep in mind that your tune will be as good as your provided datalog.

even when remote tuning standalone ecus there should be Wideband figures included in log. otherwise it can not be done in Ray Charles mode - meaning tune can not be done blind.

This DIY is ment for Siemens MS41, Siemens MS42, Siemens MS43 users that we remote tune on dailybases 24/7 all around the world but will work on lot of other platforms as well.

Ok lets get started

there are several ways to datalog wideband in Siemens MS4x ECU's, but i prefer this one

Tools Required: A - Romraider Software


C - Wideband O2 Kit

D - USB to COM Male adapter with drivers

E - DB9 RS232 Serial to Terminal Female Adapter Connector

F - Electrical Tape G - Soldering Iron/Solder H - Wire Strippers I - Wire (about 20 gauge)

Recommended Number of People: - one person will handle it, unless you want someone to hold your beer.

Difficulty: - 2 out of 10 if you've soldered before

Time to Complete: - few hours, but is entirely dependent on having the right parts and where they are in your car.


A) Romraider Logger

Download and install free Romraider software from

once installed you will have Romraider Logger icon desktop, thats what you need.

What Romraider does: it allows user to communicate with ECU to collect user selected data and record it as log file.

Logging allows you to monitor, real-time, a number of different data parameters used by the ECU in the management of the engine. This is important to track the impact that your tuning changes have on your motor. Logging is crucial to a safe and effective tune.

Romraider logger definition file is needed to communicate with your ecu,

you can get it from here:

once you downloaded logger definition file go to Romraider logger, click settings and select "Logger Definition Location" and select the file you downloaded.

for MS4x ecus you will have to switch Logging protocol to: DS2

before starting logging you need to create log output folder somewhere for example on Desktop and name it "Logs" then select this folder in “Log File Output Location” from the Logger’s settings menu. so once you datalog some parameters they will automatically appear in this folder.


you can get it cheap from ebay:

or pay double and get tested cable from

sometimes it is tricky with drivers but once you install cable drivers properly you are good to go.

C) Wideband O2 Kit such as:

1) AEM Wideband UEGO Controller P/N: 30-4110

2) Innovate MTX-L Plus P/N:3918

3) AEM’s X-Series Wideband UEGO Controller P/N: 30-0300

Wideband O2 kit is tuning tool that allow users to accurately monitor the Air/Fuel Ratio (AFR) of their engine which is critical when running forced induction or custom N/A setup.

it is not mandatory to have when you are going for OTS (Off The Shelf) tune which are made for stock cars or cars with specific mods.

D) USB to COM Male adapter

E) DB9 RS232 Serial to Terminal Female Adapter Connector

easy to use one:

if you want to solder wires yourself:

and if you are too lazy and can not do simple things you can pay 35$ and get this adapter:


once you have it all listed above, it is time to wire wideband serial output to laptop and make them talk to each other.

in this example AEM 30-4110 is used:

You need to use blue circled wires for DB9 (com) connector

AEM UEGO Black wire should go to Ground

DB9 connector Pin #5 goes to same ground

AEM UEGO Blue wire goes to DB9 connector Pin #2

Done with wiring?

OK lets get started:

1) Start your engine, and connect INPA (K+DCAN) cable to OBDII port

2) Plug other side of INPA cable into the laptop

3) Open RomRaider and click connect (Green button)

4) Select the parameters you want to record,

I suggest to select following parameters for MS4x users:

  • Engine Load

  • Engine Speed

  • Ignition Angle

  • Injection Time

  • Intake air temp

  • Coolant Temperature

  • Mass airflow (kg/h)

  • Mass airflow (Volts)7

  • Throttle position

  • Accelerator position

  • AEM UEGO Wideband (AFR Gasoline)

  • Knock Sensor1 volts

  • Knock Sensor2 Volts

  • Lambda integrator Bank 1

  • Lambda integrator Bank 2

  • SW Closed throttle

  • SW Full Load

  • SW Part Load

5) once parameters are selected make sure they are changing / moving - so it means connection is established successfully.

6) Plug the female serial connector into the usb to com male adapter,

7) plug usb cable of USB to Serial adapter into laptop

8) In Romraider Select "Plugins", then select AEM UEGO 9600 (when using AEM Wideband as shown in example).

9) Select the COM Port the Wideband is connected to. You can check it in "Device Manager" and see which number is your usb to com adapter in Communiction ports.

10) you are ready to Go log!

Always make sure you have same AFR reading in Romraider as on Gauge.

when finished logging before sending log file to us open latest log file and check that AFR figures are logged and are variable not constant same!

we have had a lot of issues with customers while remote tuning that we get logs with constant 18 AFR figure in it or constant 11.2 afr figures which is wrong.

sometimes logger interrupts connection between laptop and wideband so you need to pay attention to this.

Happy logging ;)


all links are given as reference, we take no responsibility on product quality or workability!

buy at your own responsibility.


stay away from Aliexpress, Taobao, Alibaba etc sources for Wideband kits.

it will cost you double to get another one after figuring out first doesnt do job that you need!

If you have any questions feel free to ask!

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