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Comfort Access

Comfort Access is a feature that is an optional on BMW vehicles. Comfort access allows the customer to retain the key in their pocket or bag and still have the ability to start and operate the vehicle.

Comfort access has three functions, passive entry, passive go and passive exit. Passive entry allows the opening of the vehicle without having to press a button on the remote. A capacitive sensor is installed in every exterior door handle that can sense when someone is attempting to open the door. Similar to passive entry, passive exit works alike, by allowing the vehicle to be locked without having to use the remote key. There is a position on the exterior door handles that when touched relays the lock request on the CAS module. Passive go enables the engine to be started without having to insert the key into the key holder. The key is detected within the vehicle by various antennas installed indifferent ares throughout the vehicle.

The different components of the Comfort Access system are:

  • Interior antennas
  • Exterior antennas
  • Exterior door handle electronics
  • Remote control keys – The remote keys interpret the signal from the exterior door handles and emit a radio signal to the remote receiver for authentication. The remote also has a replaceable battery due to the increased functions of the remote key. If the remote is inserted into the key holder all comfort access functions are deactivated.
  • Remote control receiver – The remote receiver interfaces between the remote keys and the CAS control module to authenticate an entry or start request. The remote receiver is also activated by the Comfort Access control unit. The remote control receiver is part to the interior mirror on E81, E87, E64 and E93 vehicles. The remote control receiver is part of the aerial amplifier on E60, E61, E70, E63, E90, E91 and E92 vehicles.
  • CAS control unit – The CAS control unit is the master controller for all comfort access functions, including interfacing with the start/stop button and key holder. The CAS control unit also controls the electronic steering lock.
  • Start/Stop button – The engine can be started by pressing the start/stop button with the brake and/or clutch depressed.
  • JBE – The JBE is responsible for unlocking the vehicle via signal sent from the CAS control module.
  • Remote key holder – Is required on vehicle without Comfort Access. The remote key must be inserted in the key holder to start the engine. On vehicle with Comfort Access, the remote key can be inserted in the key holder if the battery in the key is discharged in order to start the vehicle.
  • KGM/KBM
  • Comfort Access control unit

An authenticity check is required for all comfort access functions. The authenticity check is similar for all functions; it is just performed by different system antennas. The exterior door handle electronics are triggered by a capacitive sensor within the door handle. The exterior door handle electronics locate remote keys via antennas in the door handles; they determine whether the remote key is within operating range. The exterior door handle electronics send a signal to the CAS control unit and initiate registration of remote controls with the CAS via remote receiver radio signal. The CAS now evaluates all the signal information and authorizes vehicle entry. Engine start is initiated in the same way only using the interior antennas and remote receiver.

  • Special note: Comfort access will allow the vehicle to be locked while the engine is running.
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