Checking the SRS System

Checking the SRS system

Checking the SRS system




When the ignition is switched to position II or III, CAN network communication is checked, there is a status check of the internal supplemental restraint system (SRS) functions (4/9) and a status check of all directly connected components, such as:
- driver airbag (8/123)
- passenger airbag (8/124)
- belt tensioners (8/33, 8/34, 8/55 8/56 and 8/62)
- seat belt tensioners waist driver (8/92) (only certain markets)
- belt pretensioner waist passenger (8/93) (only certain markets)
- side impact sensors (7/108, 7/109, 7/115 and 7/116)
- side impact sensors (pressure sensors) (7/208 and 7/209)
- inflatable curtains (8/66 and 8/67)
- SIPS bags (8/51 and 8/52)
- front seat belt buckles (3/93 and 3/94)
- rear belt buckles (3/217, 3/218 and 3/219) (certain markets only)
- adaptive steering column (8/99) (USA/CAN only)
- seat position sensor (3/255 and 3/256) (USA/CAN only)
- adaptive seatbelt force limiters (8/128 and 8/129)
- switch, front passenger airbag (3/157) (not USA/CAN)
- occupant weight sensor (OWS) (7/93) (USA/CAN only)
In addition to these directly connected components, communication with Closing velocity module (CVM) (4/125) is also checked.
The supplemental restraint system module (SRS) transmits information via the controller area network (CAN) to the driver information module (DIM) (5/1) indicating that this test is in progress. The central electronic module (CEM) (4/56) also transmits the parameter values during the status check.
The driver information module (DIM) then lights the SRS warning lamp. The SRS warning lamp is lit while the supplemental restraint system (SRS) is being checked. When the supplemental restraint system (SRS) has been tested and no faults have been detected, the SRS warning lamp goes out.
If a fault is detected during the check it will be indicated in one of the following ways, depending on how serious it is:
- the SRS warning lamp remains lit and a warning text is displayed in the driver information module (DIM)
- the general red warning lamp lights and a warning text is displayed in the driver information module (DIM)
- information light is lit and any text message is shown on the Driver information module (DIM).
The driver information module (DIM) continuously transmits a signal to the supplemental restraint system module (SRS) via the controller area network (CAN) with information about whether the SRS warning lamp is working or not. The red general warning lamp lights up if the SRS warning lamp stops working. If the CAN communication between the supplemental restraint system (SRS) module and the driver information module (DIM) fails, the SRS warning lamp lights up and text is displayed in the driver information module (DIM). If the faults disappear and the driver information module (DIM) can transmit information to the supplemental restraint system module (SRS) and the status of the SRS warning lamp is OK, the warning lamps will return to normal function.