BitBox BMW GearBox

It’s not an actual physical gearbox part, but an ECU/TCM tuning module for the BitBox tuning system.

BitBox software modules are used by automotive tuners and technicians to access and modify control units (ECUs/TCMs) on vehicles for diagnostics, calibration, tuning, or repair purposes.

The BitBox BMW GearBox module connects to your BMW’s Transmission Control Module (TCM) through the diagnostic connector.

It supports reading and writing data on:

• Bosch GS8.60.2 TCMs (used with ZF 5HP24 automatic transmissions)

• Siemens GS20 TCMs (used with GM 5L40 transmissions)

The software automatically corrects checksums during read/write operations so modified data remains valid.