Component Description For Front Reversible Emergency Tensioning Retractors - GF91.40-P-4020FR
Model 257, 290
up to model year 2021
Location
The reversible emergency tensioning retractors are located at the bottom of the respective B-pillar.
Tasks
The reversible emergency tensioning retractors have the task of tensioning the seat belt of the driver or front passenger seat in certain hazardous situations by actuating an integrated actuator motor. Securing the vehicle occupants in the seat in a more optimal fashion minimizes the consequences of a potentially impending accident. If the seat belt adjustment function is active, the seat belt slack is additionally reduced when the seat belt is fastened.
The tasks are subdivided as follows:
- Reading in of signals
- Evaluation of input factors
- Transmitting signals
Reading in of signals
The following signals, among others, are read in via the user interface CAN (CAN HMI):
- Status of driver seat belt buckle switch (S68/3)
- Status of front passenger seat belt buckle switch (S68/4)
- Crash signal
- PRE-SAFE® status
- PRE-SAFE® stage
- Status of seat belt adjustment function
Evaluation of input factors
The read-in input factors are evaluated by the integrated microprocessor whereupon the integrated components are actuated and the CAN signals issued.
Transmitting signals
The reversible emergency tensioning retractors send e.g. the request to display a fault message via the user interface CAN to the instrument cluster (A1).
| Technical data Designation | Unit | Values | Tolerance range | Comment |
|---|---|---|---|---|
| Front reversible emergency tensioning retractors | ||||
| Voltage supply | V | 13 | - | On-board power supply voltage |
| Voltage limits | V | 9 | - | Lower limit value |
| V | 16 | - | Upper limit value | |
| Power consumption | MA | 64 | - | Readiness (Circuit 15 ON) |
| A | 40 | - | When tightening the seat belt for t = 300ms | |
| A | 10 | - | When tightening the seat belt after t = 300ms | |
| MA | 0, 1 | - | No-load current during bus idle | |
| Reverse polarity protection | - | - | - | The reversible emergency tensioning retractors are equipped with internal reverse-polarity protection. |
| Special features | - | - | - | The reversible emergency tensioning retractors can be activated over the user interface CAN. If one of the two reversible emergency tensioning retractors is connected with the incorrect polarity to the user interface CAN, no fault is shown for the remaining user interface CANs in the vehicle. The reversible emergency tensioning retractors are not activated in the event of any CAN polarity reversal, and they do not display any function as they cannot receive any valid CAN signals. |
| Flash capability/coding capability | - | - | - | Yes/yes |
| Under voltage threshold for retraction cancellation | V | 7, 5 | - | - |
| Wiring diagram, reversible emergency tensioning retractor | PE91.40-P-2200-97XBA |