TCU (Transmission Control Unit) Remapping

Vehicles fitted with automatic transmissions normally have a TCU (Transmission Control Unit) fitted. All the transmissions aspects ( Gear shift, torque limiter, etc) are controlled through this TCU.  The ECU and TCU work side by side in harmony sending all the live data to all the components throughout the vehicle. We often recommend having the TCU remapped alongside the ECU. This ensures the TCU and ECU keep working in harmony, whilst getting everything possible from the vehicle, with regards to performance and drive-ability

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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 at 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 TCUs have more manipulations available. Some have advanced options like: 

  • Launch Control
  • ​​Full Manual Mode
  • Kickdown Delete.


Please note:

 

Not all TCUs will ‘need’ to be tuned and not all TCUs 'can' be tuned, it depends on the application and the desired vehicle performance. Please see below a list of TCUs that can be tuned. 

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

For information based on each one, please feel free to email us.