Passive Entry via door

WARNING: This page is about a different car, the 2008 BMW 760Li. However, it is still accessible from the selected car via links, so may be relevant.

The vehicle is unlocked when the outside door handle is gripped or pulled. Condition: The ID transmitter must be located no further than 1.5 m from the aerial in the outside door handle.

Ideally, the user should carry the ID transmitter in a pocket.

First, the user is authenticated (= authenticity check).

The data transferred during the authenticity check is of course encrypted.

If the ID transmitter authenticity check is successful, the user will be granted access to the vehicle. The central locking is unlocked. The door can be opened.

Unlocking is supported by an electric motor for added comfort.

The same principle is applied for the authenticity check for Passive Entry and Passive Go.

Authenticity check using the example of Passive Entry:

Trigger signal at outside door handle electronics via the capacitive sensor.
Request sent to outside door handle electronics to locate an ID transmitter via the aerials in the outside door handle. All ID transmitters associated with the vehicle and located outside of it are included in the search (low-frequency radio signal at 125 kHz).
The search determines whether an ID transmitter associated with the vehicle is located in the operating range of the aerials in the outside door handle.
At the same time, the outside door handle electronics send a message to the CAS control unit via the sub bus (K-bus).
All ID transmitters located register with the CAS control unit by sending a radio signal via the FBD receiver (high-frequency radio signal, country-specific, e.g. 868 MHz).
The CAS control unit decides which of the registered ID transmitters will be used for the subsequent authenticity check.
This selection is sent to the outside door handle electronics in a message via the K-bus. At the same time, a request is sent to the outside door handle electronics to carry out a selective scan of the ID transmitter concerned.
All ID transmitters not picked up in this scan end reception readiness for the communication operation currently in progress.
The ID transmitter picked up via the selective scan responds by sending a radio signal to the CAS control unit via the FBD receiver (high-frequency radio signal at 868 MHz).
The CAS control unit evaluates the response and, if it is valid, authorizes Passive Entry.
The vehicle is unlocked.

An electric motor unlocks the door lock early to enable the vehicle to be opened quickly enough. This ensures that the door unlocks whenever the user pulls the outside door handle to its full extent.
The tension sensor is set up with redundancy to the capacitive sensor (e.g. capacitive sensor 1 deactivated due to long-term lack of use).
When the tension sensor detects the "Outside door handle pulled" signal, the door is unlocked. The door can be opened by pulling on the outside door handle again.