Gearbox Remapping Bishopbriggs. Our gearbox remapping in Bishopbriggs tunes the TCU (transmission control unit) on DSG, ZF and Powershift gearboxes for faster shifts, raised torque limits and higher clamping pressure. Pair it with an engine remap or run it standalone — either way your gearbox in Bishopbriggs will shift with more purpose and less slip.