What are the symptoms of a faulty auxiliary battery in a Mercedes-Benz S-Class?
2 Answers
Multiple function failures: When the auxiliary battery in a Mercedes-Benz malfunctions, it indicates a failure in the car's engine battery, which should not be taken lightly. Once the auxiliary battery fails, many functions will stop working, such as auto start-stop, reverse radar, seat heating, HOLD, etc. If the auxiliary battery in a Mercedes-Benz fails, it needs to be repaired at a 4S dealership and cannot be resolved automatically. Slow car startup: When the auxiliary battery fails, it can cause the car to start slowly, result in issues with some circuit controls or insufficient power, and may also lead to excessively low voltage in the car's battery pack, which can cause other faults. It is necessary to promptly visit an auto repair center for maintenance and replacement.
I've been driving a Mercedes S-Class for almost ten years and have encountered issues with the auxiliary battery several times. The main symptoms include a battery warning light appearing on the dashboard or displaying 'Auxiliary System Malfunction.' When starting the vehicle, the engine ignition becomes sluggish, not as smooth as usual. The door lock control sometimes fails, requiring multiple presses to unlock. The central screen frequently pops up error warnings like 'Low Voltage' or 'Power Supply Abnormal.' The audio and air conditioning functions may suddenly cut out—last time, my music stopped on the highway before I realized the problem. The start-stop system completely failed, automatically restarting every time I stopped. Later, at the dealership, they found unstable voltage, and it cost over two thousand to replace the battery and fix it. I think addressing it early is crucial; otherwise, driving at night with weakened headlights can be very dangerous and compromise safety.
