Seats - Service Information BMW M5 E60/E61

ACTIVE SEAT BACK WIDTH ADJUSTMENT

E60, E61

Scheme 1

Introduction

During cornering, lateral forces are exerted on the occupants in the upper body region.

The active seat back width adjustment counters these forces: The backrest side section on the outside moves inwards slightly. This provides the occupants with support in the upper body region. Active seat back width adjustment is available for the driver's seat and the front passenger seat (option 4MF).

In contrast to the seat back width adjustment which has been familiar until now, the seat back width is now adjusted actively.

2 control units control the active seat back width adjustment

1. Active seat back width, driver's seat (ALBFA)
2. Active seat back width, front-passenger seat (ALBBF)

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Introduction (Con't)

Note. Option 4MF only available in conjunction with option 456, not option 455. Option 4MF "Active seat back width adjustment" is only supplied together with option 456 "Front comfort seat". Option 4MF cannot be combined with option "455 Active seat" (installation area for the control unit).

Note. Active seat back width adjustment also in M5. Active seat back width adjustment was developed by BMW M GmbH (as an integral part of option 4MA "M multifunction seat for driver and front passenger").

From 09/2005, the "Sport" map has been changed to M5. Please refer to " SYSTEM FUNCTIONS ". This change will also be incorporated into the E60/E61 at a later date.

Also New - From 09/2005 The vehicle electrical system has been modified. The body gateway module (KGM) supersedes the safety and gateway module (SGM).

Brief Description Of Components

The following components deliver signals for the active seat back width adjustment

Center Console Switch Cluster

2 buttons for active seat back width adjustment are located in the center console switch cluster (SZM)

1. 1 button for the driver's side
2. 1 button for the front passenger's side

These buttons have 3 positions. This means that 3 different characteristic maps can be selected

1. "Comfort"
2. "Normal"
3. "Sport"

Scheme 7

The center console switch cluster (SZM) is connected to the K-CAN and K-bus. The K-bus connects the SZM to the seat adjustment control panel on the driver's seat and front-passenger seat.

How It Works

The active seat back width adjustment can only be activated when the engine is running.

Each of the 3 LEDs represents one characteristic map for the active seat back width adjustment. The characteristic map is stored in the control unit for active seat back width adjustment.

1. Characteristic map 1: comfort
2. Characteristic map 2: normal
3. Characteristic map 3: sport

If the button for active seat back width adjustment is pressed for longer than 1or 2 seconds

1. The active seat back width is deactivated.
2. All LEDs are switched off.

If half of the range of adjustment has been exceeded when the active seat back width adjustment is activated, the seat back width is opened to the halfway position. This ensures a sufficiently large range of adjustment.

Control Panel For Seat Adjustment

Each seat has a seat adjustment control panel. The width of the backrest can be adjusted individually using the "OPEN" and "CLOSE" buttons. The control panel is connected via a K bus to the center console switch cluster (SZM).

Construction

The seat adjustment control panel is connected to the center console switch cluster (SZM) via the K-bus.

Scheme 8

The seat back width can be manually adjusted using the seat adjustment control panel. Adjustment is also possible when the ignition key has been removed (from 09/05: provided terminal 30g is switched on).

If the active seat back width adjustment is activated, adjustments can only be made to the backrest side section which is not activated. Possible positions: completely open or half closed).

Sensors In The Active Seat Back Width Adjustment Drive

The drive incorporates the following sensors

1. Limit-Position Switch
2. 2 Hall Sensors
3. Temperature Sensor

The temperature sensor protects against overheating.

The other sensors monitor the drive's position and direction of rotation.

Installation Location

One drive is mounted on the seat mechanism for each left and right backrest side section.

Scheme 9

The drive consists of an electric motor with a flange-mounted transmission. The transmission meshes with the backrest side section adjustment using a gear-tooth system. The following sensors are built in to the electric motor

1. 1 Limit-Position Switch
2. 2 Hall Sensors
3. 1 Temperature Sensor

The drive closes the seat back width from the fully opened position in approx. 1 second (at maximum closing speed).

The seat back width adjustment drive is activated by a pulse-modulated signal from the control unit (0% to 100%). If the curve is long enough, the maximum range of adjustment for the outside backrest side section is used. The maximum range of adjustment depends on the manual adjustment of the seat back width.

1. "Comfort" characteristic curve: maximum range of adjustment - 80% (with 50% pulse width modulation)
2. "Normal" characteristic curve: maximum range of adjustment - 100% (with 65% pulse width modulation)
3. "Sport" characteristic curve: maximum range of adjustment - 100% (with 80% pulse width modulation; 85% for M5)

The limit-position switch is a Hall sensor. It identifies when the seat back width is completely open (= zero position).

The control unit identifies the position and rotational direction of the electric motor using the Hall signals. During this process, increments are counted either upwards or downwards. The sequence of signals enables the control unit to identify the rotational direction. The Hall sensors are monitored by the control unit (signal at least every 200 ms when electric motor is activated).

The temperature sensor measures the temperature of the electric motor. In the event of overheating, activation of the electric motor ceases until the temperature falls below the permissible value.

(ALBFA) Active Driver Seat Back Width & (ALBBF) Active Front Passenger Seat Back Width

Note. Several control units are involved in the active seat back width adjustment

The ALBFA control unit and the ALBBF control unit activate the active seat back width adjustment drives (driver's seat or front passenger's seat). The signals are transmitted to the PT-CAN.

With active seat back width adjustment, a control unit is installed for the driver's seat and the front-passenger seat respectively. Each control unit is mounted under the seat on the seat mechanism.

Scheme 10

The ALBFA control unit and the ALBBF control unit are connected via the PT-CAN (powertrain CAN) to the bus system. The control units are of the same construction. The ALBBF is differentiated by an additional earth connection on the control unit. Each control unit has 3 plug-in connections to the vehicle's system.

Pin Assignment

PIN ASSIGNMENT FOR ALBFA OR ALBBF CONTROL UNIT CONNECTORS X11548 (ALBFA) OR X11551 (ALBBF), 8-PIN

PIN ASSIGNMENT FOR ALBFA OR ALBBF CONTROL UNIT CONNECTORS X11549 (ALBFA) OR X11552 (ALBBF), 10-PIN

PIN ASSIGNMENT FOR ALBFA OR ALBBF CONTROL UNIT CONNECTORS X11550 (ALBFA) OR X11553 (ALBBF), 10-PIN

DSC: Dynamic Stability Control

The DSC control unit sends the following signals for seat back width adjustment to the PT-CAN

1. Vehicle road speed The DSC control unit calculates the car's road speed using the signals from the 4-wheel speed sensors.
2. Longitudinal acceleration The DSC control unit calculates the longitudinal acceleration using the signal from the DSC sensor.
3. Lateral acceleration The DSC control unit calculates the lateral acceleration using the signal from the DSC sensor.
4. Yaw rate The DSC control unit calculates the rotation around the vertical axis using the signal from the DSC sensor.
5. Steering angle The steering angle sensor determines the steering angle in the steering column switch cluster (SZL). The SZL sends the signal to the DSC control unit via the F-CAN (chassis CAN).
6. Steering-angle rate The steering angle sensor also determines the steering angle speed in the steering column switch cluster (SZL). The SZL sends the signal to the DSC control unit via the F-CAN (chassis CAN).

DME or DDE: Digital Motor Electronics Or Digital Diesel Electronics

The engine control unit delivers the "Engine running" signal.

The seat back width adjustment is only activated when the engine is running.

SMFA and SMBF: Driver's Seat Module And Front Passenger's Seat Module

The seat module controls the seat memory. The seat module sends a CAN message in order to set a specific seat back width (memory for seat back width adjustment).

Signal path: seat module -> K-CAN -> safety and gateway module (SGM) -> PT-CAN -> ALBFA or ALBBF

Drive For Active Seat Back Width Adjustment

Note. The following components are controlled

A drive for seat back width adjustment is located in the backrest of the seat on the left and right-hand side.

During cornering, the drive on the outside adjusts the seat back width.

The backrest side section is moved in the process.

For more information, refer to SENSORS IN THE ACTIVE SEAT BACK WIDTH ADJUSTMENT DRIVE .

LEDs In The Center Console Switch Cluster

3 LEDs are positioned above the button in the SZM. The LEDs are activated depending on which characteristic map is selected (Comfort, Normal, Sport).

For more information, refer to CENTER CONSOLE SWITCH CLUSTER .

System Functions

The following system functions of active seat back width adjustment are described

1. Active Seat Back Width Adjustment
2. Undervoltage And Overvoltage
3. Easy Entry Facility For Driver's Seat And Front Passenger's Seat
4. Centering For Setting Of Seat Back Width Adjustment
5. Soft Start And Soft Stop Of Seat Back Width Adjustment Drive
6. Memory For The Seat Back Width
7. Special Feature Of Mdrive In M5

If the active seat back width adjustment is activated, the outside backrest side section is activated during cornering. The drive adjusts the backrest side section during cornering until the lateral forces are supported.

A stable seat position is thus maintained.

For actuation, the following signals are evaluated

1. Car road speed
2. Lateral acceleration
3. Longitudinal acceleration
4. Yaw rate (rotation around the vertical axis)
5. Steering angle
6. Steering-angle rate
7. The engine must be running

From 09/2005 in M5 On stretches of road with many bends, the two armrest side sections are incorporated into the "Sport" map. The winding stretch of road is detected by the changing lateral acceleration. This change will also be incorporated into the E60/E61 at a later date.

Undervoltage & Overvoltage

The active seat back width adjustment control unit detects undervoltage and overvoltage.

Undervoltage On-board supply voltage less than 9 volts.

Overvoltage On-board supply voltage greater than 16 volts.

Easy Entry Facility For Driver's Seat & Front Passenger's Seat

For ease of access, the seat back width adjustment is opened completely.

The Easy Entry facility for the driver's seat is activated under the following conditions

1. Driver's door is opened
2. Terminal R is switched off when the driver's door is closed

The Easy Entry facility is deactivated at terminal 15 ON. The stored seat back width is approached.

The Easy Entry for the front passenger seat is activated under the following conditions

1. Door on the passenger's side is opened when the seat belt has not been fastened.

Centering For Setting The Seat Back Width Adjustment

Following every manual adjustment, the position of the backrest side section is tracked. During this process, compensation is made for any difference between the left and right position. Compensation is made if the signals from the Hall sensors vary by at least 5 Hall pulses.

Centering begins 1 second after a seat back width adjustment has been made. If one attempt fails, the centering process is repeated 2 seconds later.

Active centering is interrupted by manual adjustments.

If the active seat back width adjustment is activated, the seat back width is not tracked.

Soft Start & Soft Stop Of Drive For Seat Back Width Adjustment

The start and stop for the drive is specially controlled.

Soft start and stop of the seat back width adjustment drive leads to a

1. Decrease In Power Consumption (No Voltage Peaks)
2. Decrease In Noise During Adjustment

The soft stop also prevents overrun of the drive.

Memory For The Seat Back Widths

The following positions for the seat back width can be stored in the memory

1. 2 positions for each personalized key: memory button 1 and 2 (on control panel for seat adjustment)
2. the last setting selected for the key which is currently used (only for the seat back width memory on the driver's seat)

The last setting selected is stored for the key which is currently in use as follows

1. 10 seconds after a manual seat back width adjustment
2. A memory key or the memory button is pressed (triggered by the seat module)
3. Terminal change from terminal 15 to terminal R

The seat module sends a CAN message to the seat back width adjustment control unit. The control unit activates the stored seat back width position.

Special Feature Of MDrive In M5

The "MDrive" button can be found on the steering wheel of the M5. If MDrive is selected, a message is sent from the engine control unit via the PT-CAN. This message causes specific adjustments in the vehicle to be made.

The required settings are selected by the user via iDrive at the Central Information Display (CID).

Settings can be selected for the following systems

1. Engine Control
2. Suspension
3. Dynamic Stability Control
4. Active Seat Back Width Adjustment

If the seat back width adjustment control unit receives the message, the characteristic curve set in CID is selected. The LED in the center console switch cluster (SZM) which corresponds with the selected setting lights up.

If another characteristic curve is subsequently selected at the SZM, the setting in CID is not overwritten.

Operation

The maximum adjustment range depends on the seat back width which has been set manually.

1. "Comfort" characteristic curve: maximum range of adjustment - 80% (with 50% pulse width modulation)
2. "Normal" characteristic curve: maximum range of adjustment - 100% (with 65% pulse width modulation)
3. "Sport" characteristic curve: maximum range of adjustment - 100% (with 80% pulse width modulation; 85% for M5)

PRECONDITIONS FOR ACTIVATION

The active seat back width adjustment is deactivated if the engine is switched off.

The control unit retains the characteristic map selected if the ignition is switched back on again 15 minutes after terminal 15 OFF (run-on time).

NOTES FOR SERVICE STAFF

The following information is available for service staff

1. General note: Refer to «GENERAL INFORMATION FOR SERVICE STAFF ON SEAT BACK WIDTH ADJUSTMENT: E60, E61»(/bmw/m5/e60e61-2004-2010/remont/seats/#seats-service-information__general-information-for-service-staff-on) .
2. Diagnosis: Refer to «INFORMATION ON ACTIVE SEAT BACK WIDTH ADJUSTMENT DIAGNOSIS: E60, E61»(/bmw/m5/e60e61-2004-2010/remont/seats/#seats-service-information) .
3. Encoding/programming: N/A

Subject to change.

General Information For Service Staff On Seat Back Width Adjustment: E60, E61

When the seat back width adjustment drive has been removed, the voltage for the function check must not exceed 5 volts. Higher voltages may damage the drive by causing blockages.

Note. Use the special tool provided for the function check of the drives. If the seat back width adjustment drive has been removed, only carry out the function check using special tool 61 2 070.

Initialization

Once repairs have been carried out on components, the seat back width adjustment must be initialized. To initialize the seat back width adjustment, a service function is available for diagnosis.

Path: Service functions -> Body -> Active seat back width for driver's side or front-passenger side

Initialization is required under the following conditions

1. Following replacement of ALBFA control unit or ALBBF control unit.
2. Following replacement of a drive for the active seat back width adjustment.

The zero position of the drives is identified during initialization. The fully opened seat back width is defined as the zero position.

Both drives open simultaneously until the zero position is reached. The zero position is identified by a signal from the limit-position switch. Initialization is then completed.

An initialization may also be triggered at the seat adjustment control panel. To do this, keep the "OPEN" button for the seat back width adjustment pressed for 15 seconds.

See also:
• SYSTEM FUNCTIONS
• SENSORS IN THE ACTIVE SEAT BACK WIDTH ADJUSTMENT DRIVE
• CENTER CONSOLE SWITCH CLUSTER
• GENERAL INFORMATION FOR SERVICE STAFF ON SEAT BACK WIDTH ADJUSTMENT: E60, E61
• INFORMATION ON ACTIVE SEAT BACK WIDTH ADJUSTMENT DIAGNOSIS: E60, E61