Siemens GK30 SMG TCU

The Sequential Manual Transmission (SMG) is an automated manual transmission (some documents also call it AMT for that reason). The driver has only a brake pedal and accelerator. The clutch is controlled by the TCU.

In the E46 exist two different SMG transmissions, a 5-speed and a 6-speed version. Both are produces by ZF. The main difference of this two transmissions are the TCU, the number of gears and the different housing. Both TCU's have the same designation GS30/GK30, but they have different CPU's inside. Both TCU's are manufactured by Magneti Marelli.

SMG 5-speed transmission (GS5S31BZ)

All 5-speed TCU had the part numbers 62000.022.0x and CFC2058.0x on their housing. These numbers are not BMW part numbers. The OEM part numbers are depending on the software version and not on the used Hardware. For this reason, the part number of BMW is not as important as the other two numbers.

SMG 6-speed transmission (GS6S37BZ)

The 6-speed TCU had the part numbers 62000.034.0x and CFC2258.0x on their housing.

PCB Layout 6-speed TCU

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