BMW 7 Series: Functions

Unlocking/locking the Vehicle

The vehicle unlocking/locking procedure is initiated by the following system components:

• ID transmitter
• Mechanical key/spare key
• Exterior trunk button (only unlocks the trunk)
• Central-lock button
• Interior trunk button on the A-pillar (only unlocks the trunk)
• Outside door handle *
• Central locking button * trunk.

* Vehicle equipment for Comfort Access.

The central locking system activates the following system components:

• Central locking, driver's and front passenger door
• Central locking, rear doors
• Central locking, fuel tank
• Trunk central locking system (with automatic soft-close drive).

The following example shows the signal path when the trunk is unlocked.

Fig. 12: Unlocking/Locking Signal Path Diagram (Trunk Unlocked)

COMPONENTS DESCRIPTION CHART

  1 - ID transmitter
  8 - Central locking, driver's door
  2 - Rear window antenna
  9 - Central locking, fuel filler flap
  3 - Remote control receiver in diversity module
10 - Trunk central locking system
  4 - Car Access System 4 (CAS 4)
11 - Trunk automatic soft-close
  5 - Junction box electronics module (JB)
12 - Footwell module
  6 - Relay for central locking
13 - Door contacts
  7 - Central locking, front passenger door and rear doors

Functional Procedure

Unlocking

Pressing the Unlock button on the ID transmitter causes an encrypted remote control signal to be transmitted.

The antenna in the rear window forwards the remote control signal to the diversity module. The diversity module remote control receiver demodulates, processes and then sends the signal to the Car Access System on the LIN bus.

If the vehicle is in sleep mode, the remote control receiver wakes up the Car Access System via the LIN bus for reduced-consumption operation. This allows the Car Access System to receive the request which was sent out by the ID transmitter. The ID transmitter has already been checked in the remote control receiver. If the result of the check is positive, the remote control receiver forwards the request via the LIN bus. If the request is authorized, the Car Access System wakes up the vehicle and causes the vehicle to unlock. The Car Access System thereby gives the junction box electronics module permission to unlock the central-locking drive.

The junction box electronics module then activates the relay and power output stages and triggers the unlocking of the vehicle.

NOTE: The Car Access System is responsible for communication over the LIN bus.

This means that the diversity module only passes on a LIN bus signal when instructed to do so by the Car Access System 4. This applies to vehicles not currently in sleep mode.

Locking

The vehicle can only be locked once the footwell module has evaluated the door contacts and the Car Access System 4 has reported that the driver's door is closed.

The further signal progression for locking the vehicle corresponds analogously to the signal progression of the unlocking procedure.

During the vehicle locking process, all central locking drives are moved into the "Lock" position. The central-locking drives in the doors are additionally moved into the "centrally-locked" position. Following the central arrest procedure, the locking buttons in the doors are mechanically separated from the central locking drive system.

The vehicle can now no longer be unlocked using the locking buttons in the doors.

Central locking button

The central locking button can be used to lock and centrally lock all vehicle doors.

The central locking button is located on the underside of the trunk and can therefore only be used with the trunk open.

Additional information is presented under the Central locking button section, which follows.

Center-lock Button

The vehicle can be locked/unlocked with the center-lock button.

If the center-lock button is not being pressed, the junction box electronics module receives a high signal (battery voltage approximately 12 V). The high signal changes to a low signal (approximately 0 V) as soon as the center-lock button is pressed.

The junction box electronics module evaluates the change from the high signal to the low signal and locks/unlocks the vehicle.

In order for locking or unlocking to take place, the driver's door and front passenger door must be closed.

Mechanical Key/Spare Key

The mechanical key/spare key is used to unlock/lock the driver's door. Should the ID transmitter fail, e.g. if the battery is flat, it is still possible to access or lock the vehicle.

Driver's-door lock barrel

The footwell module evaluates the Hall sensors for the lock barrel in the driver's door. The Car Access System 4 is informed of the change in status via the K-CAN2.

The Car Access System 4 enables the vehicle unlocking/locking procedure. The junction box electronics module triggers the unlocking/locking of the vehicle.

The normal procedure for unlocking or locking using the mechanical key occurs within a period of approximately 20 ms to 1 second. Evaluation of the lock barrel Hall sensors occurs within this period of time.

NOTE: Turning the mechanical key in the driver's-door lock barrel too quickly or slowly, means that only the driver's door will be mechanically unlocked or locked. In such situations, the central locking system does not operate.

Trunk lock

The trunk lock can be unlocked by using the mechanical key in the lock barrel, and then opened.

NOTE: If the anti-theft alarm system is fitted, unlocking the trunk may trigger an alarm.

To close the trunk, the trunk must be pushed into the trunk lock. As soon as the locking pawl reaches the pre-locking position, automatic soft-close begins and closes the trunk.

NOTE: In the F01, the trunk lock is pulled closed via an automatic soft-close drive.

Slamming the trunk closes the trunk so quickly that automatic soft-close is not activated.

Locking Button on Vehicle Doors

All four doors can be mechanically locked separately with the locking button.

The inside door handle of the door to be unlocked must be pulled twice before the door will unlock.

However, the junction box electronics module does not activate central locking.

If the vehicle is centrally locked, the locking knobs are mechanically disconnected from the lock. It is thus no longer possible to unlock the vehicle either via the locking knobs or by pulling twice on the door handle. On vehicles with an anti-theft alarm system, this also activates the system.

Car Access System 4

As soon as the Car Access System 4 receives the signal from the remote control receiver, it checks whether the ID transmitter is valid and belongs to the vehicle. Only if the check is successful will the Car Access System 4 forward the request to the central locking.

The check, also referred to as authentication, takes a few milliseconds. As the master control unit of the central locking system, the Car Access System 4 grants authorization for control of the central locking system.

The junction box electronics module receives the enable via the K-CAN2.

Junction Box Electronics Module

The junction box electronics module is the The trunk central locking system is activated slave control unit which unlocks/locks the directly via a power output stage. entire vehicle. The unlocking/locking relays are located in the junction box electronics module. The following relays are activated:

• Relay for unlocking/locking central locking
  • Driver's door.
• Relay for unlocking/locking central locking
  • Rear doors
  • Front passenger door
  • Fuel filler flap.

Footwell Module

The footwell module monitors the Hall The request to lock the vehicle, for example, is sensors of the door contacts. Opening or not executed while the driver's door is open. closing a door causes a change in status of the door contact in question to occur.

The junction box electronics module receives the current status of the door contacts from the footwell module via the K-CAN2. The junction box electronics module passes the status of the door contacts on to the Car Access System 4.

Unlocking the Trunk

The trunk can be unlocked via the ID transmitter and the exterior or interior trunk button, and then opened.

ID transmitter

The ID transmitter is used to trigger the unlocking of the trunk by means of a brief (approximately 500 ms) press on the trunk symbol button.

The junction box electronics module executes the unlocking of the trunk.

The motor in the trunk lock is activated via the power output stage in the junction box electronics module.

NOTE: If the vehicle is fitted with the automatic trunk actuation option, the trunk symbol button must be pressed and held for longer than 1.2 seconds.

Exterior trunk button

As soon as the vehicle is unlocked, the trunk can be opened with the exterior trunk button in the trunk. The button switches to ground when the exterior trunk button is pressed.

The button is monitored by the junction box electronics. When the signal of the button changes to low, the trunk is unlocked and can be opened.

Fig. 13: Identifying Exterior Trunk And Exterior Trunk Button

COMPONENTS DESCRIPTION CHART

1. Exterior trunk button
2. License plate light

Interior trunk button in the A-pillar

As soon as the vehicle is unlocked, the trunk can be unlocked and opened by pressing the interior trunk button.

The button is integrated into the A-pillar and switches to ground.

The Car Access System evaluates the button and sends the signal for the junction box electronics module over the K-CAN2. The junction box electronics module evaluates the message and triggers the trunk to unlock.

Closing the trunk

Gently pressing the trunk into the trunk lock triggers the automatic soft-close drive.

A microswitch in the trunk lock is activated by the locking pawl being located in the prelocking position. The drive electronics for automatic soft-close assess the change in status as a starting signal.

The drive then pulls the rotary striker closed via a Bowden cable. As soon as the locking pawl engages in the main locking position, the automatic soft-close drive is stopped.

NOTE: The automatic soft-close drive serves to ensure that the trunk closes both safely and securely.

Special Functions

Automatic locking (personal profiles)

At speeds in excess of 16 km/h (10 mph), the vehicle locks automatically. The speed signal is supplied by the Integrated Chassis Management.

The vehicle is unlocked in connection with Comfort Access as soon as terminal 15 is switched off.

NOTE: Various functions of the central locking system can be individually customized using "personal profiles".

Unlocking after a crash

A locked central locking system is unlocked as soon as the Car Access System 4 receives a crash message from the advanced crash safety management.

After this crash message is received, the central locking controls are blocked.

The controls are only enabled again after Advanced Safety Crash Management (ASCM) stops sending the crash message or if, after 10 seconds, the crash message is no longer received.

Selective unlocking

With corresponding coding, the vehicle can also be unlocked selectively. In this case, initially the driver's door is unlocked. The rest of the vehicle is unlocked in response to a renewed unlock request.

Central Locking Button

A new function for the central locking system is the ability to activate central locking from the trunk.

The central locking button is located on the underside of the trunk. Whether or not the button is present depends on which equipment is installed on the vehicle.

Pressing the central locking button locks and centrally locks all vehicle doors.

NOTE: The central locking button is only accessible with the trunk open.

The button status is evaluated by the Car Access System. If the vehicle is in sleep mode, it must first be woken up.

The Car Access System recognizes that the central locking button has been pressed and locks and centrally locks the car as appropriate.

CENTRAL LOCKING BUTTON REFERENCE CHART

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