TCU (Transmission Control Unit) Remapping

TCU Remapping Angus Scotland Brand Autos

Cars that have automatic transmissions come with a Transmission Control Unit (TCU), which manages different aspects of the transmission such as shifting gears and regulating torque. The TCU communicates with the Engine Control Unit (ECU) by exchanging real-time data through the car’s network system. To improve a car’s performance and drivability, it is often suggested to remap both the ECU and TCU at the same time during tuning, to ensure that both control units remain synchronized and fully optimize the car’s overall performance.

The number of parameters that can be changed is dependant on the application, however here are some of the typical changes:

  • Shift Speeds – Increasing the speed in which the gearbox changes gear.
  • Torque Limiters – Increasing the TCU torque limiters ensures the transmission cannot limit the performance of the engine.
  • Hydraulic Pressure – Increasing the hydraulic pressure can increase clutch clamping pressure to prevent clutch slip on highly tuned vehicles.
  • Shift Points – Changing the rpm limiter of the engine is often not possible without modifying the TCU software.


Some TCU’s have a higher level of manipulation available and advanced options like the following can be activated: Launch Control, Full Manual Mode, Kickdown Delete.

Please note: Not all TCU’s will ‘need’ to be tuned and not all TCU’s can be tuned, it depends on the application and the desired vehicle performance. Below is a list of TCU’s we tune on a regular basis.

VAG DSG / S-Tronic
BMW ZF (6 Speed and 8 Speed)

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