Belt Hand-Over
Belt Hand-Over
Coupes have larger doors. In that the B-pillar is further towards the rear, it is not as easy to reach the belts as in Sedans.
When fastening the seat belt, unergonomic twisting of the body would be necessary. In surveys in the USA, this led to negative assessments by customers.
BMW is using a belt hand-over as series standard for the first time on the E92.
Advantage: more convenient reaching for the belt.
The belt hand-over on the passenger's side is only activated if the seat is occupied.
This function logic is a competitive advantage.
Brief description of components
The following components are described for the belt hand-over:
Belt hand-over
When retracted, the belt hand-over is integrated in the side trim panel and invisible. It fits harmoniously into the design of the passenger compartment. The belt hand-over consists of the following components:
The belt hand-over moves out to a maximum of 350�mm. Extension and retraction take less than 2�seconds.
Belt hand-over controller
The belt hand-over controller activates the drive of the belt hand-over. The position of the drive is indicated to the belt hand-over controller by a Hall sensor in the drive.
The end position of the extended belt hand-over is picked up by another Hall sensor. The end position is signalled to the belt hand-over controller.
Both signals are sent by the belt hand-over controller via the LIN bus to the footwell module (FRM).
Belt lock contact
The front belt lock contacts detect whether the belt is inserted in the belt buckle. The signal is sent to the multiple restraint system (MRS).
Seat occupancy detection
The seat occupation detection on the passenger's side detects whether the seat is occupied. The CAS supplies the seat occupation detection with terminal R.
The following control modules are involved in the belt hand-over function:
FRM: Footwell Module
The footwell module (FRM) activates the two belt hand-over controllers for the driver's and passenger's side. The belt hand-over controllers are connected across an LIN bus on the footwell module. The software for activation is in the footwell module.
MRS: Multiple Restraint System
The belt lock contacts on the driver's and passenger's sides are connected to the multiple restraint system (MRS). The MRS control module is connected to the FRM via the body CAN. The MRS control module forwards the signals from the belt lock contacts.
CAS: Car Access System
The Car Access System (CAS) is the master control module for the terminal control.
The CAS sends the terminal status on the bus.
The CAS also signals the seat occupation detection on the passenger's side, terminal R.
JBE: Distribution box in the junction box electronics
Together with the junction box electronics, the distribution box forms the junction box. The distribution box supplies the belt hand-over controller with terminal 30g.
System functions
The following system functions are described for the belt hand-over:
- Function logic for extension of the belt hand-over
- Function logic for retraction of the belt hand-over
- Blocking protection, overheating protection
- Undervoltage detection and overvoltage detection
Function logic for extension of the belt hand-over
The belt hand-over on the driver's side is extended according to the following function logic:
The belt hand-over on the passenger's side is extended according to the following function logic:
Function logic for retraction of the belt hand-over
The belt hand-over on the driver's side and passenger's side is retracted according to the following function logic:
The belt hand-over on the passenger's side is also retracted according to the following function logic:
Blocking protection, overheating protection
As blocking protection on extending, the belt hand-over reverses 20�mm if it encounters an obstacle. The Hall sensor in the drive runs the blockage identification of the belt hand-over.
The front section of the belt hand-over folds back mechanically on retraction to provide blocking protection.
The drive of the belt hand-over has overheating protection. After activation of the drive a number of times, the overheating protection is activated.
Overvoltage detection and undervoltage detection
A voltage greater than 16 Volts is regarded as overvoltage.
A voltage less than 9 Volts is regarded as undervoltage.
In both cases, the belt hand-over is not activated.
Notes for Service department
General information
NOTE: blocking protection on retraction of the belt hand-over.
The front section of the belt hand-over folds back mechanically on retraction to provide blocking protection. This is not a defect.
NOTE: belt hand-over controller with 2 earth connections.
In order to distinguish the installation location, the belt hand-over controller on the passenger's side has an additional coding pin. Terminal 31 is applied on the coding pin.
Country-specific versions
US version
Instead of the seat occupation detection, the passenger seat occupation mat US is connected to the multiple restraint system (MRS).
No liability can be accepted for printing or other faults. Subject to changes of a technical nature