Checking The SRS System
When the ignition key is turned from 0 to I, II or III, the status of the internal functions in the supplemental restraint system module (SRS) (4/9) is checked, as well as all directly connected components such as:
- driver airbags (8/30 and 8/61)
- passenger airbags (8/31 and 8/32)
- seat belt tensioners (8/33, 8/34, 8/55, 8/56, 8/62, 8/94, 8/95)
- side impact sensors (7/108, 7/109, 7/115 and 7/116)
- front and rear inflatable curtains (8/66, 8/67, 8/96, 8/97)
- SIPS bags (8/51 and 8/52)
- frontal impact sensor (7/178, 7/179)
- front seat belt buckles (3/93, 3/94).
At the same time, the supplemental restraint system module (SRS) transmits data 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 indicator lamp. The SRS indicator lamp is lit while the SRS system is being checked. When the SRS system has been tested and if no faults have been detected, the SRS indicator lamp goes out.
If a fault is detected, the lamp remains lit and a warning text is displayed in the text box in the combined instrument panel. 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 indicator lamp is working or not. The orange general warning lamp lights up if the SRS indicator lamp stops working. If this lamp also stops working, the red general warning lamp is used. If the CAN communication between the supplemental restraint system (SRS) module and the driver information module (DIM) fails, the red lamp in the general warning lamp lights up and text is displayed in the text box in the combined instrument panel. If the fault disappears and the driver information module (DIM) is again able to transmit information to the supplemental restraint system module (SRS) indicating that the status of the SRS indicator lamp is OK, the general warning lamp will not light but the SRS indicator lamp will take over.
It may take up to 3 minutes before the seat belt buckles indicate whether they are functioning correctly.