What is the plug on the negative terminal of an Audi battery?
2 Answers
It is used to connect the battery charge monitoring sensor. Rain sensor: The rain sensor is an optical system in the infrared band. It has a light-emitting component that emits infrared rays. When the glass surface is dry, almost 100% of the light is reflected back, allowing the sensor to receive a large amount of reflected light. In this case, the system defaults to clear weather and does not activate the windshield wipers. Function of the sensor: The automatic rain-sensing wipers detect rainfall and adjust their speed accordingly, eliminating the need for manual adjustment. This ensures the driver's clear visibility at all times, making driving safer and more comfortable. It enhances both driving comfort and safety.
The first time I saw the small plug on the negative terminal of the Audi battery, I thought it was just an extra part. It wasn’t until a casual chat with a friend that I learned it’s actually an intelligent monitoring sensor, specifically designed to track the battery’s status, constantly checking current and voltage to prevent the car from failing to start or the battery from draining. After driving for a few years now, I feel Audi’s design is quite thoughtful—it optimizes the start-stop system, helping me save fuel and money. However, if you recklessly unplug it, the system might throw a fault code, affecting the headlights or even the engine start. During routine maintenance, I make it a habit to check if the plug’s wiring is loose to avoid trouble, since repairs can be costly and time-consuming. I’d advise fellow owners not to tamper with it—it may be a small component, but it’s crucial for safe daily driving.
