What causes the Mercedes-Benz E260 to display a protection system malfunction?
3 Answers
Protection system malfunctions are most likely caused by damaged airbag sensors or faulty seat belt sensors. There may also be other reasons. Spark plug issues: After removing the spark plugs, disconnect the fuel injector fuse, start the vehicle, drain the unburned fuel, clean and heat the spark plugs, then reinstall the spark plugs and fuse. Finally, start the vehicle again. If there are any trouble codes, they can be cleared. Fuel flow obstruction issues: It could also be due to obstructed fuel flow, possibly caused by lack of fuel pressure in the supply line or long-term contamination of the fuel lines. Simply park the car in a warm environment for a while, and it should start. Alternatively, cleaning the fuel system can resolve the issue. Battery discharge issues: During cold winter temperatures, failure to turn off certain electrical devices can prevent the vehicle from starting.
I drive a Mercedes-Benz E260, and last time the protection system malfunction warning also popped up, which freaked me out so much that I immediately pulled over to check. I found that 80% of the time, this issue is caused by the camera behind the windshield being covered with tree sap. After rain, mud sticking to the radar sensor at the bottom of the rearview mirror can also trigger false alarms. Another possibility is software glitches—the Mercedes infotainment system occasionally requires manual updates. Then there’s wiring damage, like rodents chewing through it or water ingress during car washing, which could blow a fuse. Of course, the most frustrating scenario is when the sensor itself is faulty. Last time, the dealership’s diagnostics showed that the radar sensor at my front right corner had a crack from a small stone impact. This protection system is linked to autonomous emergency braking and seatbelt pretensioners, so any issues need immediate attention. Never attempt DIY fixes—if the autonomous braking fails while driving, it could be extremely dangerous.
Mercedes-Benz owners are no strangers to that protective system malfunction alert, right? I've summarized the common causes as follows: sensor contamination is the most frequent, especially when the radar probes in the front grille get covered in mud; electronic system glitches, particularly prone to false alarms in humid or rainy conditions; wiring issues like rodent damage or connector oxidation; and hardware failures such as radar modules being hit by flying stones. Once, my car reported a fault on the highway, but wiping the probes with a wet wipe at a service area fixed it. It's important to note that this system controls collision warnings and automatic braking, so when it malfunctions, blind spot monitoring also stops working, making highway lane changes especially dangerous. If you notice a fault, first clean the sensors. If restarting the system doesn't help, get it checked at a shop immediately—never take chances.
