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MaxxECU online help

The BMW DCT CAN protocol is not yet released, still under testings and development.

BMW DCT related links

BMW DCT Wiring information.


BMW INPA diagnostic tool.

BMW DCT error codes.

BMW DCT TCU firmware flashing.

DCT clutch relearn.

MTune - DCT Settings.

MTune - DCT Control.

DCT Realtime Data description.

DCT hardware upgrade.


Will be updated when released!



How does the BMW TCU torque control works

(even more information here for the gecky customers...)


All torque values transmitted to the TCU is between -1023 and 1023Nm.

The transmitted torque value has a direct relation to the DCT clutch pressure, but be aware, DO NOT send to much torque to the TCU on lower loads (since that will not give you a smooth shift transition).

If you engine produces max 600Nm on the dyno, there is no reason to send 1000Nm if you do not want to make sure you have maximum clutch pressure.

The standard torque table values will probably work for most setup, but might require a little bit of tweaking.

The torque strategy transmitted to the TCU is HIGHLY advanced, but we have tried to simplify everything to make it easier for you to tune in, therefore, only one torque value is available to be tuned.

The shifting operation uses the pedal position (drivers torque choice) and the SPORT(335)/Drivelogic(M3) mode (1-6) as a simplified and automatic shift hardness setting. Mode 6 + full throttle = maximum shift hardness.



Launch / burnout torque control


Torque during launch

Torque control table when the launch control digital input is active. This is the torque (in Nm) which is transmitted to the TCU during launch. As soon as the launch button is released, the regular torque control tables is used.

Note: A value between -600 and -1023 is necessary to not burn the clutches during building of boost.


Burnout rpm

To be able to do a burnout with the DCT gearbox, it might be needed to activate the digital input DCT clutchkick/burnout mode to force a negative torque value to be sent to the TCU during engine rev-up, when exceeding this RPM value, rapidly transmitting the regular torque value to simulate a clutchkick to make the wheel spin.



Torque control


DCT torque

This is the main torque table, transmitting the torque value to the TCU, as written above, the transmitted torque value has a direct relation to clutch pressure.


Example torque values:

Idle: -100 to 50Nm, keep it as low as possible or prevent vehicle from moving without having the brake pedal engaged, to high number on idle will give TCU error codes.

Light load: try to keep the value as low as possible, without having to much clutch slip.

Middle load: Same here, do not send to much torque, it will give you a "rough" shifting operation, but must be high enough to prevent clutch slipage.

High load: It i safe to send full torque on high load, but be sure not to send to much torque before the engine actually has almost the same torque load.


Note: If the transmitted torque value differs to much from the calculated clutch torque (inside the TCU), a DCT error code will be thrown and shifting operations will go sideways.


DCT torque correction

The torque correction table, mostly used during launch to make a small clutch slip to prevent wheels from slipping.

100% = no correction, uses the above and main torque table.

Note: Be careful here, especially with a lot of power, not to let the DCT clutches to slip for a to long period.






How to make a burnout with the DCT gearbox...