E46 BMW M3 with SMG II CSL Flash

Did you know your BMW E46 M3 with SMG II transmission can be programmed with the shifting performance tweaks and rev-matching improvements which are implemented in the E46 M3 CSL? The transmission hardware is the same between the US spec E46 M3 and the CSL, with the only difference being the CSL’s more aggressive and elegant shift logic. SFBMWcoding now provides this service for the modification to be done on US spec E46 M3’s.


If you want to experience the shift control, rev matching, and SMG logic of an E46 M3 CSL but have a US spec E46 M3, you can now take advantage of the tweaks by upgrading your DME parameters and transmission software with the E46 CSL variables! One can be used without the other, but for the full benefit of the CSL improvements, you will need to flash both the engine maps and the CSL SMG II transmission software together.


What does flashing the US Spec E46 M3 with CSL DME tuning parameters do?

There are several maps or shift logic plans set in the E46 CSL DME which differ from the regular BMW M3 DME parameters. In order to port them over to the non CSL M3, we copy the maps which control up-shift recognition, timing of engine speed regulation, and torque ramp-up from the BMW E46 CSL DME. These are different on the CSL vs. Non CSL M3’s, and give a more responsive and aggressive shift with smoother CSL rev-matching.  Want to learn more?

“The CSL received a more advanced drivelogic software package than the standard M3 that was capable of making shifts in 0.08 second. Also, this advanced CSL Software package can also be uploaded to the standard M3 SMG DME to get the CSL gear shift performance increase.” –wikipedia (but .08 shift reference taken from caranddriver.com). 

CSL maps


The E46 CSL remap ports the values from the E46 CSL over to the E46 M3 but it does not modify any fuel, air, or engine combustion timing values. The E46 CSL remap ports the shift and rev logic but not the engine power values which makeup the power differences between the CSL and regular US E46 M3.

What does flashing the US E46 M3 with CSL SMG transmission software do?

In order to take full advantage of the E46 M3 DME CSL parameter update, we recommend flashing the CSL transmission software onto the SMG II transmission to smooth out and refine the shifting characteristics. Doing so also allows using launch control at 4500 RPMs (not that you’ll ever use it!). Want to learn more?




Can I flash the DME parameters without the SMG transmission software, and vice-versa?

Yes. We have fully tested flashing just one without the other. We believe updating the E46 M3 with E46 M3 CSL DME tuning parameters alone, account for about 85-90% of notable performance improvement, while upgrading to the CSL SMG transmission software accounts for the remaining 10-15% (subjectively). We feel the CSL DME tune parameters alone greatly increases shift responsiveness with shortened blips when up-shifting, and much improved down-shift rev-matching. When we flash the CSL transmission software together with the E46 CSL DME parameters, the shift events become more refined and polished, culminating in smoother shifting performance. The two go hand-in-hand and make for a great update.


Cool! What other options can you do to upgrade the E46 M3 DME?

While we’re on the topic of upgrading the E46 M3 DME remap which incorporates the E46 CSL tune, we also offer other neat options such as programming sport button memory (remember last setting the sport button mode was in), disabling the cold start sequence (don’t want to wake your neighbors in the morning?), removing speed governors, and enabling shift lights in BMW E46 M3s with manual transmissions. Just ask us about them!


Does flashing the E46 M3 with the E46 CSL tune cause different behaviors?

After upgrading to the BMW E46 CSL software, most US E46 M3 users notice much more aggressive shifting in program modes 4 and up. Be ready to kick into gear after the flashing is done, but dont worry, this behavior is normal.

Users also note that there is an overall sportier feel which is a very worthwhile upgrade.


How long does upgrading the E46 M3 with E46 CSL software take?

The entire process should take less than 20-30 minutes. Upon arrival, we hook up a battery charger to the vehicle and download a backup of your current DME software. After the backup is downloaded we modify the read dump and upload it back to your DME. The process is quick, easy, and painless.


What if I don’t like the new changes with the E46 CSL flash?

In the very slim chance that you do not like the upgraded shift logic and better rev matching provided with the E46 CSL tune, we make a backup of your stock ECU and can easily revert back to it in case you are not satisfied.


I want this, but I don’t live in the San Francisco bay area, do you provide this service remotely?

Yes! We offer this service remotely.