The Supplemental Restraint System (SRS) is a fundamental safety feature in Mercedes cars. A functional SRS will ensure car occupants’ safety in the event of a crash. This system works with several components to provide additional protection to drivers and passengers.
Unfortunately, the SRS system can malfunction over time and trigger a warning light on your instrument cluster. You may see this warning light when starting or driving your car. But why does this light turn on, and your vehicle fails to start?
I provide reasons for the SRS malfunction Mercedes car won’t start. You’ll also learn what the SRS malfunction means and what to do if your car won’t start.
Question: What is the SRS and How Does It Work?
As stated earlier, the SRS is one of the safety features in Mercedes cars that provides extra protection to occupants in the event of an accident. The system comprises the following components:
- Airbags
- Airbag control unit
- Crash sensors
- Belt force limiters
- Child occupancy sensor
- Emergency tensioning devices
These components must be in good working condition for the SRS to provide additional safety. So, how does the system work?
The SRS relies on various sensors to detect an impact in the case of a car crash. These sensors will send signals to the airbag control unit. Then, the control unit interprets the signals to know if the deployment of the airbags is necessary.
Your Mercedes car has front, side, curtain, and knee airbags that may deploy depending on the type of accident. Moreover, the belt force limiters adjust the seatbelts during a crash to ensure occupants remain seated.
Question: What is SRS Malfunction?
The SRS malfunction means there are issues with the airbag system that can prevent the airbags from deploying. This system monitors the operation of the above components to ensure they’re working correctly. If one of them is defective, the system will detect this problem and turn on a warning light.
It’s worth noting that the SRS is a self-managing system. When you turn on your Mercedes, the system performs self-diagnosis to ensure all the components are fine.
The SRS warning light will appear when you turn on the ignition in normal situations. Then, the system will confirm that everything is in good working condition and turn off the light after around five seconds.
However, if there are issues within the system, such as bad sensors or defective airbags, the light will stay on constantly. You’ll need to examine the system to identify and fix the problem. Failure to do this will cause your airbags to not deploy during an accident.
But what causes the SRS light to stay on after ignition and the Mercedes fail to start?
Answer: 5 Reasons for SRS Malfunction Mercedes Car Won’t Start
Several issues can lead to the Mercedes SRS malfunction car won’t start. When this happens, you may use a more advanced OBD-II scanner to read the fault codes. In most cases, your Mercedes will fail to start and display the SRS warning light due to the following:
Low Battery Voltage
Start with the battery, as it’s the leading cause of cars not starting. A weak battery will cause dash controls and on-board computers to act up. These components can lead to your Mercedes SRS malfunctioning and the vehicle not starting.
Listen to the starter when turning the key before opening the hood to check for a weak battery. Does it make a clicking noise? If not, a weak battery could be to blame.
Next, try to crank your engine and check if the lights will dim. Lights going out when trying to crank the engine indicate a weak battery.
If your car battery is weak, examine the terminals and connections for any issues. You can also test for a bad alternator.
Jumpstart or recharge the battery to see if the Mercedes will start. Take the battery to a local parts store to have it tested. You’ll need to replace the battery if it’s too old or defective.
A drain on the battery can also lead to low voltage. The local parts store or dealership can perform a parasitic battery drain test to identify and fix the cause of the battery drain.
Blown Fuses
Fuses protect your car’s electrical components in the event of short circuits or electrical surges. There’s a fuse for the Electronic Ignition Switch (EIS), starter circuit, and fuel pump. If these fuses blow out, the SRS may malfunction, and your Mercedes won’t start.
You can locate the fuses in the box and inspect them to see if they appear burned out. Alternatively, use a multimeter or test light to identify the blown fuses. Remove the blown fuses and replace them with new ones.
Fuel Problems
Mercedes SRS malfunction car won’t start may result from issues in the fuel system. If there’s no fuel in the tank, the car won’t start, displaying the SRS warning light. So, check the tank and refill it if necessary.
If the fuel tank checks out, but nothing happens, you’ll need to diagnose the fuel lines for defects. Clogged fuel injectors or a damaged fuel pump could be to blame. Clean the injectors and repair or replace the pump.
Defective Brake Light Switch
SRS malfunction Mercedes car won’t start could result from a defective brake light switch. This switch sends signals to your car’s computer when you apply brakes. It also plays a significant role when starting the vehicle.
Unfortunately, this switch is prone to wear or damage, causing it to malfunction. A bad brake light switch will affect the Drive Authorization System, preventing the car from starting. Replacing this switch will resolve this issue.
Electronic Steering Lock Failure
The starting problem and SRS malfunction could result from a failing electronic steering lock. When this lock fails, it won’t release the steering, and you won’t hear a noise when you insert the key. The car computer will detect this problem and prevent the engine from starting.
You’ll, therefore, have an SRS warning light, and your car won’t start. In this case, you’ll need to call a professional to repair the lock or have the car towed to a repair facility or dealer.
Note: After fixing the above, the SRS warning light may remain on the dash, even after starting the engine. In this case, you must use an advanced OBD-II scanner to reset the system. It’s also advisable to allow a technician to examine the car to identify the cause of this warning light.
Wrapping Up
The SRS malfunction Mercedes car won’t start is an all-too-common issue most drivers encounter. Most issues that prevent vehicles from starting may trigger this problem.
So, before seeking professional help, check the battery, fuel system, fuses, and brake light switch. Call a professional to diagnose and resolve the problem if all these check out.