TCU (Transmission Control Unit) Remapping

Vehicles equipped with automatic transmissions are normally fitted with a TCU (Transmission Control Unit). The TCU controls all aspects of the transmission’s functionality e.g. gear shift and torque limitation. The TCU works in harmony with the ECU (Engine Control Unit) by sending and receiving real time data across the vehicles network system. When tuning a vehicle, it is often recommend to have the ECU and TCU remapped simultaneously, this ensures both control units continue to work in harmony and will help to fully optimize the performance and driveability of the vehicle.

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, please click on each link for detailed information.

VAG DSG / S-Tronic
BMW ZF (6 Speed and 8 Speed)
MB DCT
FCA (FPT TCT)