Mercedes Benz collision prevention assist is a useful feature to protect drivers from potential accidents by forwarding collision warnings and applying the brake in an emergency, thus offering them more peace of mind while driving.
The warning collision prevention assist plus inoperative can be a reason for your worry as you already rely on this assistant and don’t know what to do if something is wrong with it.
There’s no need to seek help from anywhere else; our article has all the information you need to clear your problem. Let’s keep reading!
About The Collision Prevention Assist Plus
What Is It?
We all know that sometimes for some reason, people don’t pay attention or are distracted while driving. Mercedes collision prevention assist plus is a newly invented technology by Daimler to protect drivers in this case.
The system can sense the object in front of you and give you some signals when there might be a crash.
You may see a red warning on the dashboard if you come too fast to the front vehicle or hear a beeping sound if you don’t stop. In some cases, the function will activate the brake to minimize possible damage.
Collision prevention assist plus is installed in Mercedes models that have been produced since 2015. It’s considered a must-have default system and will be installed free of charge.
How Does It Work?
258 collision prevention assist plus has a short-range radar sensor to scan the object moving in front of your car. It’s a small black box located under the bumper near the license plate.
Once you turn it on, the system starts to detect the possible close vehicles within the area of 80m forward, making it helpful especially when you’re tired.
Here is how the great function of Mercedes collision prevention assist works.
Imagine your car is operating on a highway and reaching the car in front of you at a fast speed; the system will display a red warning message telling you to keep your distance from that car to avoid crashing its rear.
The message will keep popping out in the instrument cluster until you’ll take some action.
If you don’t do anything, such as slow down, use the brake, or even increase your speed, you will hear the beep noise.
Should you still ignore that sound and continue at high speed or the vehicle slows down, the Mercedes collision avoidance system will also apply the brake to save you from a potential crash.
Besides alerting you of the danger and applying the ideal level of braking, there’s one more amazing thing about this function.
Suppose you’ve stopped at the traffic lights and begin to move, and you don’t notice that the car in front of you suddenly uses the brake.
The system will also brake immediately with the necessary amount of brake force, so you’ll not hit that car.
What Does Collision Prevention Assist Plus Inoperative Indicate And Causes?
Mercedes collision prevention assist plus inoperative means the warning accident system has stopped working.
In this case, it can’t scan and detect the potential danger (the error code is Mercedes c10c700 indicating a maladjusted radar sensor). Plus, the automatic braking system is also suspended.
Since the system has two main functions, when it fails to work, both functions stop working at the same time.
Besides, some issues may arise, such as difficulty pressing the gas pedal, trying to speed up, and limp mode transmission.
You may want to drive with the code c10c800 “CPA” Triggered Warning, but fixing it as soon as possible is highly recommended to eliminate the discomfort while driving.
So, What Is The Reason?
2015 Mercedes c300 collision prevention assist plus inoperative can be due to a faulty mechanic part or software.
1. Dirt
The radar sensor may not work properly because of dirt, snow, or other debris gathered in front of the car. If, after cleaning, the warning is still there, you may need to remove the front bumper to diagnose the sensor.
2. Interference
Driving near sources of electromagnetic radiation, such as a radio station, can be a reason for the assist plus Mercedes changes to inoperative.
3. Low Battery Voltage or Insufficient Power
When you shift the engine to park but forget to switch off the ignition, you’ll likely see the warning message. Operating your vehicle on idle mode or running it for 30 minutes may help.
Meanwhile, when you haven’t used your car for a long time, or your battery has died, or you’ve just had a battery replacement, all of these lead to insufficient power to run the system.
4. Extreme Temperature
When the weather is too cold or too hot, the extreme heat or coldness can affect the system, causing it to work improperly.
5. A Poor Engine Control Unit (ECU) Connections
Dirty, loose, or overspray pins can lead to communication problems with some parts, such as the gas pedal, throttle actuator contacts, and proximity sensors.
When diagnosing, you may get a fault code Mercedes-Benz DTC u105cfc Communication with the control unit ‘COLLISION PREVENTION ASSIST’ that has a malfunction.
How To Fix?
Restart The Vehicle In A Safe Place
Find a safe place to pull over and turn off the engine for two minutes. If the battery partially drained, you may need to wait 15 minutes before the Mercedes collision prevention assist reset.
Clean The Bumper
If the above solution doesn’t work, check the bumper and remove any debris stuck there to unblock the sensor. Restart the car to check if the sensor is working.
When the bumper is heavily rusted, you can consider painting the front bumper to prevent further corrosion.
Replace The Sensor
Your sensor still not working after removing the debris on the bumper means there can be something wrong with it. Take out the bumper and look for a small smartphone-size black box.
Slowly unplug the cable and check. If you see the connectors are moisture, you’d better change the sensor since it was damaged by water.
The replacement is also necessary when you sense a bad smell coming from the part, indicating a short circuit and burnt.
Update The Software
Assist plus inoperative can be because your software is out of date. Call the dealer to ask for an update so that the system can work smoothly without showing errors.
Diagnose The Module
Use Foxwell for Benz, iCarsoft MB II, and Autel MaxiDAS full system scanner to diagnose other problems. It can read and clear the specific fault codes, bringing your system back to normal.
FAQs
How Can You Reset The Accident Preventing System?
You can reset Mercedes GLC collision prevention by letting your vehicle stay idle for 10-15 minutes. It helps recharge and reboot the system.
For Toyota cars, click here to learn how to reset the pre-collision system.
Can I Deactivate The Accident Avoidance System?
Yes, you can do it by selecting the option from the car function menu. However, consider keeping it active for the sake of your driving safety.
What Car Applied Collision Prevent System?
The accident warning is standard on Mercedes-Benz G-Class. And for the Volvo S60, S80, XC60, and XC70 models, the City Safety is equipped.
You can also find the system on the BMW 760i, Acura ZDX, Honda Crosstour AWD, Toyota Land Cruiser, and Hyundai Equus.
Conclusion
You should not ignore the collision prevention assist plus inoperative warning as the function is a proven life safer for drivers.
With the radar sensor, the system can scan the possible colliding object in front of you, then alert you by popping the message, giving audible sounds, or even assisting you in applying proper brake force.
Since it’s a useful function, you’d better take care of it. If the message displays once a year and restarting your car can help, it may not be a source of concern.
However, when it happens more often, consider trying the solutions above to solve the issue. Bringing your car to the repair shop is also ideal, as they know what to do and can troubleshoot your problem quickly.