The airbag warning SRS light could come on due to a defective Child Seat Occupancy Recognition Sensor installed in the passenger seat.
If you had an auto mechanic diagnose the car or if you scan the airbag module yourself using Launch Creader VII Diagnostic Scanner you will find one of the following errors:
- Child seat recognition seat sensor
- Seat occupied recognition control unit
- Passenger seat occupancy sensor
This article will clarify the Airbag / SRS light problems due to a defective child seat recognition sensor on the passenger seat. This article discusses the child recognition sensor and the pros and cons of disabling the light using a child recognition emulator.
This article is for information purpose only and it may not be complete or completely accurate. Do not disable safety features on your car. We recommend that you replace the defective sensor instead of disabling the child seat recognition feature or installing an emulator.
What is the Automatic Child Seat Recognition Sensor (AKSE)?
A weight sensor is installed on the passenger seat of Mercedes-Benz cars, known as a child seat recognition sensor. This sensor is found not only on Mercedes-Benz E-Class W211 or S-Class W220 but also on other models such as CLS, CLK-Class, C-Class, and ML-Class. Most Mercedes-Benz models since 2000 have the child seat recognition sensor installed. This is a great safety feature, but it does fail quite frequently.
When a child sits in the front passenger seat, this is detected by the child seat recognition sensor. And if you were to get in an accident with the child in the front passenger seat, the passenger airbags would NOT deploy. That’s because if the airbags deploy and a child is sitting in the front, they can cause injuries to the child.
Disable the child seat recognition sensor.
The correct method to fix this problem is to replace the child recognition weight sensor mat. Many Mercedes-Benz owners end up disabling the child seat recognition sensor instead of replacing it. The two standard methods that Mercedes-Benz owners use to eliminate the SRS warning light are installing an emulator or re-programing the Air Bag control unit. These two methods achieve the same by eliminating the child seat recognition function.
When the child seat recognition sensor is disabled and you are to get into an accident, both driver and passenger airbags will deploy. This is not a problem if no one is sitting on the passenger side, but it is a problem if a child is in the front. Front airbags deploying on children can cause serious injuries.
So owners who disable the child seat recognition sensor must be 100% sure no child sits on the front passenger seat.
How is SRS disabled via Mercedes-Benz Star Diagnostic Programming
Auto repair shops that have a Mercedes-Benz Star Diagnostic Scanner have been reported to disable the child seat recognition sensor using the scanner. They access the Airbag Control Module, then go to Contro Unit Adaptations and program the car so that there is no Seat Occupied Recognition Sensor by disabling the AKSE/SBE and switching it not to present.
Notice that a Mercedes-Benz authorized dealership will likely not disable the child recognition sensor due to safety concerns. You should consider replacing the sensor with a new one instead of disabling it. It is up to you, the owner, on which route you go; you are responsible for what you do with your car, regardless of what anyone recommends. Remember that disabling a safety feature on your vehicle may violate federal law.
If you are worried that the child recognition sensor has been disabled on your car, there is one easy way to check. Look under the passenger seat to see if the Passenger Seat Occupancy sensor has been unplugged. If someone has disabled the sensor via programming, they would also have to unplug the sensor to erase the SRS light.
Check under the passenger to ensure the child seat recognition sensor is unplugged. Here is a picture of the connector you will find unplugged if AKSE is disabled.
Airbag Light Reset Seat Occupancy Sensor Emulator
If you do a quick search on Amazon, for example, you find several listings for Seat Occupancy Occupation Sensor SRS Emulator. Owners may install an emulator that will bypass the child seat recognition feature and erase the fault code via the OBD-II port under the dashboard. While this method will also erase the SRS light, keep in mind that it will disable the child recognition feature on your front passenger seat.
The emulator generates a signal to make the airbag control module think that a person is always sitting in the front passenger seat. The front passenger seat appears as if it is “always ocupited” even if no one is sitting on it. Therefore the airbags will deploy even if a child seat is present on the front seat.
While this method will also get the SRS light erased, in the end, it still disables the child recognition safety feature. Instead of programming the car not to recognize the child occupancy sensor, you install an emulator that always tells the vehicle there is a passenger in the front. In return, the car thinks the seat sensor is working, and an adult is always sitting on it. Therefore, driver and passenger airbags will deploy in case of an accident. The critical thing to understand is that just like disabling the ASKE, installing a simulator/emulator also disables the child seat recognition feature.
If an emulator is installed, a diagnostic scanner such as the YOUCANIC full system scanner is used to clear the fault codes.
Replacing the child seat occupancy recognition sensor.
Replacing the child seat occupancy recognition sensor is the best solution to eliminate the SRS warning light. It may be more expensive and labor-intensive than disabling the feature. On the other hand, you will solve the problem the right way. Replacing the child seat recognition mat is possible but requires removing the seat. Here is a Mercedes-Benz owner that replaced his on an E-Class.
You can find a new or used Mercedes-Benz Child Seat Recognition mat on eBay and save money.
How to Reset the Airbag SRS Light yourself
Resetting the airbag srs light is very simple if you have a diagnostic scanner that works on the Mercedes-Benz airbag control unit. One scanner that we recommend that will read, erase, and clear airbag srs fault codes are the YOUCANIC full system scanner.
Remember that you can NOT erase the airbag SRS light unless you fix the problem first. Don’t assume the problem is always the child seat recognition sensor. Use the scanner mentioned above to read the fault codes first. This will give you an excellent idea of what is causing the SRS light to illuminate. Watch the video below to learn how easy it is to use a diagnostic scanner to troubleshoot the SRS light.
What is the Best Scanner to use for my Mercedes-Benz?
YOUCANIC full system diagnostic scanner is a powerful tool that can help you troubleshoot Mercedes-Benz problems quickly and efficiently. This scanner can communicate with all the control units in your Mercedes-Benz, including the engine, transmission, ABS, SRS, and more. By accessing real-time data from these control units, you can pinpoint the root cause of the problem and take appropriate action to resolve it.
Whether you’re experiencing issues with your engine, transmission, or other systems in your Mercedes-Benz, the YOUCANIC diagnostic scanner can provide valuable insight into what’s going on under the hood. This scanner can help you identify error codes, read live data, and perform special functions like reset adaptations or component tests. With this information, you can make informed decisions about repairs, maintenance, and upgrades to keep your Mercedes-Benz running smoothly.
Overall, the YOUCANIC full system diagnostic scanner is invaluable for any Mercedes-Benz owner or technician looking to troubleshoot problems quickly and accurately. With its user-friendly interface and powerful diagnostic capabilities, you can save time, money, and frustration by diagnosing and resolving issues with your Mercedes-Benz quickly and efficiently.