A Personal Site by Richard Lin aka OctaneGuy | Friday, June 23, 2006
Technical Articles
MTH Cartune USB 

This article exists to provide clarification for using the USB version of the German OBDII cable and the MTH CarTune software. You and ONLY YOU accept full responsibility for your actions for any problems that result out of following this. If you do not agree to this, then please leave this site immediately. Again, you accept full responsibility for the consequences of your actions. I do not work for, nor am I affiliated in any way with the companies mentioned in this article.

Who says that horsepower mods for your MINI need to be expensive? If you're just starting out with mods, you'll probably do an aftermarket Intake and Exhaust. You'll easily spend $500 + for these mods, and your actual horsepower gain will be very minimal. In fact, most people say you do these mods not for power but for the sounds, and any extra HP gain is just a bonus.

Enter the world of ECU mods commonly known as CHIPPING. Most ECU mods involve the removal of a component of your car that is sent out to a shop who modifies it and sends it back--usually after about $400+ later. ECU mods essentially wring out every last bit of power while potentially enabling hidden features. Manufacturers don't expect every owner to take absolute care of their cars, so they build in a lot margin of safety.

Since you're reading this page, it's likely you aren't one of those people, and are more like me, where you value cost effective mods to give you the most bang for the buck, while still cherishing your pride and joy!! The MTH Cartune mod is an inexpensive Euro$60 software that works with an OBD cable--range in price from US$80 to US$120. You simply download your ECU info, and email it to Franz, the tuner/owner at MTH, and he will modify it, and send it back! Then using the same software you downloaded the ECU info, you upload it.

It's been reported that the normal 115hp MINI Cooper gains 15 hp using 91 Octane gas or 22hp using 94 Octane. The MTH CarTune ECU mod works for any of the MINI's--from Coopers to JCW, but I've only focused on the Cooper since that's what I own. In addition, Coopers gain the MCS specific ASC along with DSC. ASC is controlled via software and is standard on the MCS, but not even an option for the MC.

Purchase OBDII Cable from Germany

Purchase CarTune Software

Read more Info on NorthAmericanMotoring

Need Help Downloading the Software???

I've got my Sony Vaio PCG-GR390 PIII- 1.2Ghz Laptop running on AC just in case
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This is how big the OBDII Interface is
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Red arrow marks location of ODB plug
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Closeup of the OBDII plug
(Click to Enlarge)

Connecting to the OBD port on your MINI is very simple. I thought I was going to have to remove parts of the car, but all I needed was to flip open a door. The OBD port is clearly marked as such. The next part of this tutorial will focus on how to configure the USB version of the Cartune software.

To configure the USB adapter, you need to realize a couple things.

1.) The Cartune software supports COM ports 1-5 only
2.) After installing the OBD USB drivers, it will add a Virtual COM port that is mapped to a free COM port for your computer. In my case, it was COM7, which isn't supported by Cartune. First thing to do when you get your USB cable is install the USB drivers from (I'm not 100% certain this is the correct page--the original page was removed, and I think this is the new one)


As with typical USB drivers, don't plug in the USB cable before installing the drivers. Just run the program after downloading it and specify a folder to install to.

Then plug in your USB cable. It doesn't need to be connected to your MINI at this time. When you plug it in, Windows XP will see that a new Device is being installed and will search for the drivers. Specify the folder you installed the drivers to. Ignore the warning that the drivers are not Windows XP certified. Once that completes, unplug the cable and shut down the computer and restart.

Now with the computer restarted, plug the cable back in. The computer should accept the cable and no longer keep asking you to install the drivers. You're 90% of the way if you got this far.

Now go to




Click the "+" NEXT TO PORTS (COM & LPT)

You should see the Virtual Com Port for CarGo Interface (COM X) with X being the number assigned

If you have a free COM port in the range of 1 - 5, it will be automatically assigned. If not, you will have to find a way to disable one of your existing COM ports, then reassign the Virtual COM port to that newly freed one. Changing the assigned Virtual COM port is as simple as RIGHT CLICKING the Virtual COM port from the current menu, and click Properties.

RIGHT CLICKING the Virtual COM port

Click Port Settings

Change the COM Port Number to one that doesn't say (In USE) and between 1 and 5.

Now go to CarTune, click PORT and Select the COM port that you just assigned the Virtual COM port to.

Once that is done, connect the OBD cable from above into the OBD socket.

Make sure all connections are secure on the OBDII adaptor

Turn the Ignition on your CAR on, all the way as if you were starting the engine. No need to actually start it though. You should now be able to click the ID button and the interface should be talking to your MINI!!!

If communication is successful, in a few seconds this will pop on your screen. If instead you get some error messages, it most likely means you have not successfully set up your USB port or COM port mapping in CarTune. Review all the settings and try again, or visit the NAM thread to discuss your problem.

Once you've successfully ID'd your car, click the Download button

After several minutes of this DOWNLOADING screen


Give the file an appropriate name, and email the resulting 2 files to Franz Hölzl *

*If you can't find these files, check the folder that you installed the CarTune software in, or check your MyDocuments folder which is typically the default file location for Windows.


Franz has finally implemented an uploader for your files, so you won't have to worry if your files were delivered or not.

If you're lucky, you'll get an email back in a few hours, or if you caught Franz on vacation, might be several days!ll Then you can just upload this back to your ECU. MAKE SURE YOU HAVE YOUR KEYCODE! THIS IS WHERE YOU ENTER IT IN THE BLUE BOX. Check the INSTRUCTIONS if you aren't sure. Make sure to specify whether you have a CVT and the highest Octane gas you use.

Remember that when uploading the files back that if you there is a problem, you run the risk of making your car into a huge paperweight!!! So take every precaution to ensure that your computer won't hiccup. Close any applications that are running in the background such as Instant Messengers, Virus Protection, etc.. Make sure your laptop has plenty of power--better to run it on AC just in case. File upload will take several minutes so be prepared for that!

How do I reload my original unchipped ECU back in?? Simple, just go to FILES and LOAD the original ORG file. It may not appear in the file list, assuming you are in the right directory, so just change the file extension pull down list to show ORG and you're set. The file type that Franz sends back is MTH. You can load back MTH or ORG files.

That's it! Hope you enjoy your new MTH Chipped MINI!!

Follow-up Notes:
I've now put a couple hundred miles on my MINI, and all I can say is WOW. My Cooper feels like a new car. There's more torque for acceleration.

Need Help Downloading the Software???

*This site is Sidekick and Hiptop Friendly!