SRS functions are checked regularly when you switch on the ignition and when the engine is running. Therefore, malfunctions can be detected in good time.

The SRS warning lamp in the instrument cluster lights up when the ignition is switched on. It goes out no later than a few seconds after the engine is started.

The SRS components are in operational readiness when the SRS warning lamp is not lit while the engine is running .

WARNING  
The SRS self-check has detected a malfunction if the SRS warning lamp:
• does not come on at all
• fails to go out approximately 4 seconds after the engine was started
• comes on after the engine was started or while driving
For your safety, Mercedes-Benz strongly recommends that you have the system checked as soon as possible at an authorized Mercedes-Benz Center. Otherwise the SRS may not be activated when it is needed in an accident, which could result in serious or fatal injury. The SRS might also deploy unexpectedly and unnecessarily which could also result in injury.
In addition, improper work on the SRS creates a risk of rendering the SRS inoperative or causing unintended air bag deployment. Work on the SRS must therefore only be performed by qualified technicians. Contact an authorized Mercedes-Benz Center.
If it is necessary to modify an air bag system to accommodate a person with disabilities, contact an authorized Mercedes-Benz Center for details. USA only: Call our Customer Assistance Center at 1-800-FOR-MERCedes (1-800-367-6372) for details.