BMW 3: Service information

Electronic emergency gearbox release

As with the conventional 8-speed automatic transmission, the GA8P75HZ also has an electrical emergency release option.

In conventional vehicles the starter motor rotates for this, and also drives the mechanical transmission oil pump via the torque converter. With help of the built-up transmission oil pressure the parking lock can be released. In the GA8P75HZ, however, the separation clutch is open without transmission oil pressure. For this reason, the transmission oil pressure for releasing the parking lock cannot be generated by the rotating starter motor. Instead the transmission oil pressure can be built up via the additional electric transmission oil pump. Alternatively the electrical machine can drive the mechanical transmission oil pump and thus build up transmission oil pressure.

In general, the following applies for the electronic and manual emergency release of the automatic transmission:

Before an emergency gearbox release, the vehicle must be secured against rolling away.

The exact procedure for electronic emergency gearbox release had not yet been defined when this product information was created.

The procedure for the implementation of the manual emergency release and the special tools required can be found in the current repair instructions.

The vehicle is only capable of maneuvering and cannot be towed after successful emergency gearbox release.

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