Table of Contents E70 Advanced Crash Safety Module Workbook Subject Page Advanced C rash Safety Module Front Airbag, Driver. Front Airbag, Passenger. Curtain Airbag . Side Airbag. Crash Safety Module . Rollover Monitoring System .. Seat Position Detection . Seat-position Recognition . Calibration of Driver Seat .. Initial Print Date: 12/06 Revision Date: rnmniruoNMnoora 2 E70 Advanced Crash Safety Module Workbook Advanced Crash Safety Module (ACSM) Model: E70 Production: From Start of Production ■BIECIIMB After completion of this module you will be able to: • Demonstrate the function of the ACSM system • Identify the different types of air bags used on the E70 • Demonstrate the Driver Seat Calibration on the E70 Advanced Crash Safety Module The safety system (ACSM) is used in the E70.The task of ACSM is to detect accident situations critical forthe vehicle occupants and to activate the necessary restraint systems selectively corre¬ sponding to the crash severity. The crash safety module performs internal diagnosis and monitors all inputs and outputs. Any faults that may occur are stored non¬ volatile in the crash safety module and indicated to the driver by way of the airbag indicator lamp in the instrument cluster. Communication with other control modules in the vehicle's system network takes place via the K-CAN and the F-CAN. In the event of a crash, a K-bus telegram is transmitted (provided a telephone is installed) via an additional separate data line to the Telematics Control Unit (TCU) and the emergency call triggered. It is possible to encode the crash safety module via the K-CAN. Diagnosis of the crash safety module takes place via the diagnosis CAN to the gateway that is located in the) unction-box ECU on the E70. Front Airbag, Driver In conjunction with the seat belt, the driver's front airbag is designed to reduce the risk of serious injury to the driver's head or thorax during a head-on collision. The front airbag forthe driver's side is located in the hub cushion of the steering wheel. The driver front airbag is equipped with a 2-stage inflator assembly. The two stages of the airbag are triggered with a time delay depending on the crash severity and use of seat belt. The two stages of the inflator assembly facilitate a restraint function adapted to the crash severity and consequently reduce additional stress on the occupants during the development phase. Index Explanation 1 Connection of firing pellet, first stage 2 Connection offiring pellet, second stage Front Airbag, Passenger Together with the seat belt, the task of the front airbag on the pas¬ senger's side is to reduce the risk of serious injury to the front pas¬ senger during a frontal crash. The 2-stage front airbag on the pas¬ senger's side is located underthe instrument panel. Deployment of the front passenger airbag breaks the instrument panel at defined points and opens a flap, which is connected to the instrument panel by means of a fabric strap. The passenger airbag opens in the direction of the windshield. The passenger airbag emerges in an upward direction and is supported on the windshield and on the instrument panel. E70 Advanced Crash Safety Module Workbook 3 «)x—1| -1- E70 Advanced Crash Safety Module Workbook (s © tstul 5 © ts Q ACSM Circuit Diagram 5 ACSM Circuit Diagram Legend 6 E70 Advanced Crash Safety Module Workbook Curtain Airbag The well-proven curtain airbag is used as the head protection sys¬ tem in connection with the ACSM on the E70. The curtain airbag extends from the A-pillar up to the C-pillarand covers the entire side section at head level. The curtain airbag inflates between the occupants and side windows or side trim pan¬ els. In connection with the side airbag in the front seat, it provides opti¬ mum protection for the occupants in the event of side impact. The curtain airbag reduces the movement of the head and other extremities towards the outside during a side crash. This results in lower neck shearforces as well as bending moments in the cervical vertebrae. In addition, it also prevents direct head contact with the side structure of the vehicle. The inflator assembly (gas generator) mounted between the B-pil- larand C-pillar is triggered in the event of a side crash. The gas flows out of the pressure vessel through the two gas lances into the curtain airbag. Simultaneously filling the curtain airbag at the front and rear ensures the air cushion is filled uniformly. The head airbag is brought into position because of the way the curtain airbag is mounted on the A-pillar and the C-pillar. The cur¬ tain airbag extends between the side window and side trim panel and the occupants. The closed system retains the structural strength and stability of the curtain airbag for several seconds Side Airbag For many years now, the side airbag has been used by BMW as an important integral part in occupants safety and protection systems. The task of the side air bags is to minimize the risk of injury to the driver/front passenger in the trunk/torso area in the event of a side impact. The side air bags are mounted in the backrest of the front seats with the aim of achieving optimum interiorfunctionality and appealing design in the E70 while also satisfying the demanding safety requirements. The task of the side air bags is to minimize the risk of injury to the driver/front passenger in the pelvic and trunk/torso area in the event of a side impact. The side airbag is triggered in response to a sufficiently strong impact from the side. The side airbag emerges through the tear seam in the backrest of the seats and inflates between the door and occupant. The air cushion between the door and occupant provides controlled damping and therefore reduces load/strain on the occupant. Crash Safety Module The advanced crash safety module essentially comprises the fol¬ lowing components: • Crash safety module • Sensors and switches • Actuators The crash safety module consists of a die cast housing with inte¬ grated plug cover. The crash safety module contains various sensors: • Rollover sensor • Low-g sensors • Longitudinal and transverse acceleration sensors The advanced crash safety module has a comprehensive sensor system.Transverse acceleration sensors in the B-pillarand door pressure sensors are used forthe purpose of side crash detection. The B-pillarsatellites also have longitudinal acceleration sensors for front and rear-end crash detection. Note: The crash safety module is located on the transmis¬ sion tunnel behind the hand brake. Various sensors (rollover, Low-g as well as longitudinal and transverse acceleration sensors) are integrated in the crash safety module and the crash safety module is inte¬ grated in the K-CAN. Rollover Monitoring System The rollover protection system is an important instrument for improving occupant protection in the event of the vehicle rolling over. The seat belt pre-tensioners and the curtain air bags are trig¬ gered in response to corresponding crash severity. The crucial fac¬ tors which determine whetherthe car overturns are not just the angle but also the angular velocity at which the car is set into the roll. All these vehicle movements can also occur after a front-end, side-on or rear-end crash. Note: The front passenger air bags are not deployed when the front seat is not occupied. However, this is not indicated by the PassengerAirbag OFF light. E70 Advanced Crash Safety Module Workbook 7 8 E70 Advanced Crash Safety Module Workbook Seat Position Detection In accordance with US legislation a system for recognizing the size of occupants must be provided forthe driver's seat. This size recognition function is based on the adjustment range of the for¬ ward/backward seat adjustment. On the E70, the exact position is determined by the actuator motor in the driver's seat. Seat-position Recognition Seat-position recognition indicates where longitudinally the seat is situated (distance to the steering wheel). In this way, the distance between the driver and the steering wheel can be detected. The ACSM requires this information so that it can fire the airbag under defined conditions. Seat-position recognition is calibrated at the factory.The positions in the front and rear longitudinal seat direction are known to the seat module. A maximum distance is available for longitudinal seat adjustment. This stretches from the mechanical front stop to the mechanical rear stop. The motorfor adjustment in the longitudinal direction generates Hall pulses overthis distance.The seat modules uses these Hall pulses to identify the current (absolute) seat position. An area for example in which a person would sit is defined in the longitudinal direction. The absolute seat position can be lost due to specific causes. The seat must therefore be calibrated. Calibration of Driver Seat The position of the driver seat in the longitudinal direction can become implausible in the course of that seat's life. This can be caused by repeatedly moving the seat forward and back. These movements can give rise to an unauthorized position delta which no longer provides fora determination of the seat position. The seat must therefore be recalibrated. Calibration is easy and can be performed by the customer him/herself following the steps in the Owner's manual. Note: These steps should turn off the Check Control Message, if not, repeat the process and if this doesn't work the system must be checked. If the seat is unable to reach the mechanical front stop, the calibra¬ tion must be performed in the service workshop. This situation can come about if, a coin is stuck in the seat-adjust¬ ment rail and blocks the adjustment travel. When repairs are made to the seat, the seat must always be cali¬ brated. This is necessary to guarantee seat-position recognition, or more precisely to increase the safe and reliable function of seat- position recognition. Switching the seat module fortest purposes for example with one from another vehicle is possible. The seat calibration will be lost however. Because the possibility of the calibration being in order when the old seat module is reinstalled cannot be ruled out, it is necessary to calibrate the seat. Note: For further details please referto BMW Service Information. Check Control Message Meaning Information in Central Information Display Seat must be recalibrated. Seat calibration necessary. Seat-position recognition mal¬ functioning! Seat-position recognition mal¬ functioning! Have the system checked by BMW Service at the next available opportunity. Rear seat not locked! Rear seat/Backrest Left or right rear seat not locked. Increased risk of injury in the event of an impact because seat belt is ineffective! The ACSM outputs a check control message via the K-CAN to the instrument cluster. The seat module can also triggerthe check control message. This is possible if for instance the Hall sensor of the longitudinal drive motor is defective.The seat must be calibrated after the repair. Note: The ACSM receives a message from the seat module via the K-CAN once a second as to whether calibration of the seat is necessary. E70 Advanced Crash Safety Module Workbook 9 10 E70 Advanced Crash Safety Module Workbook Workshop Exercise - Seat Detection Using an E70 shop vehicle perform the "Driver Seat Calibration" How do we know that the Driverseat is out of calibration? What procedure is to be followed if the Check Control Message does not go out? STEP 1 Move the driverseat forward until it comes to a complete stop. STEP 2 Move the driverseat forward once again (note a small amount of additional movement.) STEP 3 Set the driverseat to the desired adjustment position.