SOS Inoperative Mercedes

Are you familiar with SOS Inoperative Mercedes?

The features and systems of a car increase the quality of driving it. However, considering how much these systems impact the vehicle, their malfunction can be quite troublesome. The Mercedes cars are no strangers to having such issues. 

What is SOS?

The SOS button in Mercedes is made to help during an emergency. Assisting the driver and the passengers should a need arise. This button will get the emergency help needed by connecting the driver with the Mercedes call center. If the SOS system malfunctions, this connection will be impossible to establish.

SOS Inoperative Mercedes 



The warning messages are the key source of information for car owners. They will tell us if a vehicle is either malfunctioning currently or is at risk of breaking down.

When we get the SOS inoperative warning message on our display, that means that the car won’t be able to connect to the Mercedes-Benz Emergency Call System. The service center may be unreachable but more often than not, it’s the inability to properly inform the center that causes this message.

Mercedes has established its Mercedes-Benz Emergency Call System back in 2012. However, it only became standard by 2014. The system is automatically triggered if a car detects an accident has occurred or if the button is manually pressed.

The lack of functionality comes from the SOS module not working. This specific part of the car could be unable to function due to a localized problem or as a byproduct of another issue our vehicle is currently facing. We will go over a few possible causes below and see what could change the state of this warning message.

What causes SOS to be inoperative

As you can imagine, a vehicle’s components are complex and can therefore have many causes that make them break.

Ignoring the basic troubleshooting and bugs, we’ll cover the higher-profile issues that need more than a quick patch to solve. Knowing the symptoms of these issues can help resolve our problems quickly.

  1. Glitch in the system

The software systems in our cars have many causes that could make it stop working. The bugs and glitches that can occur are not unheard of.

Especially considering how complex these features can be on the software end. Of course, the glitches that happen can come from anything. Mercedes-Benz has already initiated a recall for over 200,000 cars across their lineup due to possible glitches.

The most common one involves the SIM card module included in the vehicle not working. This SIM is used to connect to the emergency call center with its wireless network. With it not working, the communication module won’t work either. [1]

  1. Low battery voltage

The battery voltage will also impact the function of the SOS system in Mercedes cars. When a car’s battery isn’t filled with enough charge to make the module work, there won’t be enough power to make the call.

Generally, this happens with older batteries or ones that have been used up a lot.

SOS inoperative message will show up in cases where low battery voltage fails to supply enough energy to the module. However, the battery will not necessarily be the key source of these issues but it’s a good thing to check before going over some other issues. [2]

  1. Wiring harness problems

The wiring harness is the part that keeps our wiring properly secured and makes sure the wiring doesn’t spill out in other parts of the car. It can also help regulate heat and protect the wiring from outside dangers or potential debris that finds its way into our car.

With the wiring harness, the SOS is kept safe no matter where you drive your Mercedes. However, if the wiring harness itself malfunctions or some parts get improperly attached, the SOS may turn inoperative.

Though it can be a bit harder to note than other issues, it pays to inspect the wiring harness before bringing the car into the mechanic’s shop. [3]

  1. Outdated phone module

Another hardware issue that may affect your car is an outdated phone module. This is an issue that may happen with older vehicles which are still using analog signals while most of the modern technology, especially mobile ones, has shifted to digital.

Though SOS inoperative message may not even appear if this problem is to blame, the calls it makes won’t go through. Automatic calls of the SOS car module will attempt to make a connection but fail in doing so.

Eventually, the error message may crop up as well, in which case it’s worth noting your car’s base specifications. Whether the vehicle includes a manual phone module and how old said module is. [4]

How to fix SOS inoperative on a Mercedes?


When we come to fixes, the cars have quite a few options. At worst, a replacement of a certain part is bound to fix the problem unless the issue extends to other components. If we do end up in such a situation, it’s likely we’ll pay quite a bit in terms of repairs. Hence why some simpler fixes are worth a try.

In terms of glitches, our best way to combat them is by utilizing software updates that deal with them. Mercedes is generally consistent with putting theirs out, especially in cases where a glitch could make an entire system inoperable.

The best thing to do is diagnose the particular software problem and follow the update guides. Alternatively, if glitches are covered under recalls, visit a nearby Mercedes shop.

Low battery voltage is another issue that can be snappily solved most of the time. Merely recharging the battery can lead to a healthier function of our car.

Not only will it make the SOS inoperable issue go away on your Mercedes, but reinforce all electricity-using parts of the vehicle. If the battery has gone bad, it may be time to replace the whole battery. Otherwise, we’ll run into far more failures along the way.

The wiring harness and outdated phone module are just things we’ll have to learn to check directly. Going under the hood can require some work and tools but it’s worth it if it prevents an issue from occurring again. Doubly so if it’s an issue that could impact our safety should a crash happen.

SOS Inoperative Mercedes

As we’ve seen, there are quite a few things that can cause this issue. However, some of the said causes may be covered under recalls from Mercedes-Benz.

It’s worth a check, especially if you got your car recently and don’t want to dish out extra money for early repairs. Additionally, warranty may come in handy in particular cases so make sure to check it for a chance to cut costs as well.

Related: ESP Inoperative Mercedes

Models with the SOS inoperative issue

As far as different models with this issue go, there are certain models that are most likely to encounter these problems. Some of the most impacted will be presented below.

In a huge recall, Mercedes-Benz has recalled over 230,000 cars. The emergency recall was issued due to the SOS being inoperative in Mercedes cars.

Considering how dangerous this could be, the action was immediate. A particular glitch disallowed the security system to let the car’s SIM card module past the filters which made it impossible to contact the emergency team.

This recall included the following car classes:

  • CLA-Class
  • GLA-Class
  • GLE-Class
  • GLS-Class
  • SLC-Class
  • A-Class
  • AMG GT-Class
  • E-Class
  • S-Class
  • SL-Class
  • GLC-Class
  • CLS-Class
  • GLB-Class
  • G-Class

That’s quite a few classes of cars that cover most of the available models. In fact, it covers most of the Mercedes cars that were in circulation when the recall was announced.

So if your car was supposed to receive said recall but didn’t, it pays to check if the glitch can be fixed now.

Related: Run Flat Indicator Inoperative Mercedes


SOS inoperative in Mercedes cars means that you won’t receive the benefits of the SOS system in cases of emergency. However, the problems with this system can endanger our lives so we better resolve the issues as soon as possible.

With the presented possibilities, we should be able to resolve the problem before it gets bad. Though in case all else fails, a professional diagnosis is suggested.

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