The CSL software flash for the SMG transmission in the E46 M3 is one of the best mods you can do to your car. The flash makes gear changes smoother and faster, and adds automated rev matching on downshifts. The flash is actually made up of 2 parts; flashing CSL software to the SMG computer with WinKFP and enabling the inertia update/rev matching in the DME with the MSS5x Binary Modification Tool.

SMG module flash: Flashed to the SMG computer itself. This smoothens out the shifting and adds the CSL’s 4500rpm launch control. Doing just this flash without the inertia update may cause extreme clutch slur (ex. clutch slipping on upshifts).

Rev matching: The rev matching feature from the CSL is coded to the DME using the MSS5x Binary Modification Tool. Makes the car blip the throttle on downshifts. This makes the biggest difference and sounds pretty cool too.

Inertia update: The inertia update was released by BMW to address the clutch slur issues that plagued many M3 CSL’s. This increases the clamping force of the clutch on upshifts, and makes S5 and S6 shift modes a lot of fun. It is also flashed to the DME using the MSS5x Binary Modification Tool.

Benefits:

• Quicker, smoother shifts
• 4500rpm launch control
• Rev matching (autoblip on downshifts)
• More forceful clutch engagement, will possibly cure clutch slur

Parts Needed

WARNING: Before you start doing anything in this guide, make sure you have a charger capable of keeping the battery fully charged during the coding process (a battery tender isn’t enough). Make sure your laptop is on a charger as any interruption while coding a module can brick it. Perform this flash AT YOUR OWN RISK! Bricking modules from improper programming is a real possibility.

Part 1: CSL Computer Flash Instructions

Step 1:

First you need to have a copy of WinKFP installed. You can download it in the BMW Standard Tools pack from our downloads page here. The Standard Tools pack will have a readme file telling you how to install the programs and set up your K+Dcan cable.

Step 2:

Import the SP-Daten files for an E46.

Step 3:

First, connect your battery charger to the battery terminals in the engine bay. Turn your ignition to ON and hook up your K+Dcan USB to OBD cable to your car and laptop. Verify you have a good connection to the car by opening INPA. If the two circles are solid black you have a good connection.

Step 4:

Open WinKFP and click Comfort Mode.

Next, click Choose ZUSB. This may also be called Choose Custom File depending on what version of WinKFP you have.

Another menu will pop up with a list of ECU families. Scroll down until you find the one called GDSMG2. The CSL software version is the one with the ZB number “7843255”. Make sure you have selected it and click on OK.

Next, press the Enter VIN button and enter your VIN.

Press OK and then Done in the bottom right corner. Next, click program. You will get a warning telling you how many times the module can still be flashed, press OK.

There will be a blue loading bar pop up that may go to 100% several times. After a little while the flash will finish. Congrats! You’ve flashed SMG software.

Part 2: Enabling Rev Matching and Inertia Update in the DME

Step 1: Install BMWFlash and MSS5x Binary Modification Tool

Both of these tools are available in our downloads page.

Step 2: Open BMWFlash and read DME.

Turn your ignition to ON and hook up your K+Dcan USB to OBD cable to your car and laptop. Click file at the top of the BMWFlash tool and then click Read DME.

When asked if you want to download the entire ROM contents, press NO. This will pull a partial read from your DME which is all that is needed for what we are doing. The flasher will download the contents of your DME to your laptop in around a minute. You will be prompted to save the file, give it a meaningful name. I recommend making a copy in case you ever want to go back to stock.

Step 3: Activate MSS5x Binary Modification Tool

If this is your first time using the MSS5x Binary Modification tool you will need to purchase a license. If you already own a license you can skip this step. These cost 20 British pounds, a very reasonable price for the amount of customization you can do with the tool. To do this, open the tool and click action at the top left corner.

Click generate license request and follow the steps to purchase a license. Your license will be emailed to you within a few minutes. Click on activate license and enter your license key. The tool will restart and you will gain access to all of its functions.

Step 4: Modifying DME file

Open MSS5x Binary Modification Tool and click Browse. Find the DME file you read from the car that you wish to modify. The tool will then populate all the fields and checkboxes with the settings your car currently has.

Check the CSL SMG Shifting / Rev Matching box and SMG Inertia Update boxes. They are circled in red in the image above. This would be a good time to make any other modifications to your DME file that you want. We have guides for various other things you can do in the E46 category.

Once you have finished making adjustments, click apply changes, followed by write changes at the bottom right corner. The tool will save a new DME file. This is the file we will write to the car.

Step 5: Flashing the DME

This is where you need to be careful. Make sure your battery charger is hooked up and working and your laptop is also on a charger. Make sure you don’t unplug the OBD cable for any reason until the flash has completed.

Open up BMWflash again. This time you will click file and then reflash DME. Click yes on the warning reminding you to have a battery charger connected.

Change the file type to BMWFlash Binary (*.bin). Select the DME file you just saved from the editor tool and click open.

BMWFlash will then flash your new DME file to the car. This may take a couple of minutes. Make sure you don’t let the connection from laptop to car get interrupted for any reason. Follow the prompt once the tool finishes and once it is done, cycle your ignition. Congrats! Your car is now coded with CSL rev matching and the inertia update!