What are the reasons for being unable to start after stalling with auto start-stop?
2 Answers
Introduction to the reasons for being unable to start after stalling with auto start-stop: Accidentally pressing the auto start-stop button in the car: Vehicles equipped with auto start-stop functionality usually have the system enabled by default. If it suddenly stops working, it might be because the auto start-stop button was accidentally pressed, causing the system to turn off. Check if the system has been disabled. Manual transmission cars: The conditions for enabling auto start-stop are a bit more complex. When parking, the system will only activate after recognizing three actions: "shifting to neutral, pulling the handbrake, and releasing the clutch." Different car models have different designs for the auto start-stop system: For example, the auto start-stop system in the new Passat requires certain conditions to be met. Specifically, the seatbelt must be fastened, the front left door must be closed, and the engine must be running. Therefore, check the user manual for any precautions. Auto start-stop system malfunction: This could be due to wiring issues or other reasons causing the system to fail. In such cases, it's best to take the car to a 4S shop for inspection and repair.
Last time I encountered a situation where the auto start-stop failed to restart at a traffic light, and later found out after towing it to the repair shop that the battery was aging. Auto start-stop is particularly harsh on battery life, especially for older batteries over three years old, as the massive current required during the start-stop moment simply can't be supplied. Starter issues can also cause failure to start; frequent start-stop cycles accelerate wear on the starter, leading to poor coil contact or depleted brushes causing it to fail. There are also sensor issues, such as a lost signal from the brake pedal position sensor, which makes the system think you're not pressing the brake and prevents starting. Additionally, insufficient fuel supply pressure from the fuel pump or aging spark plugs causing abnormal ignition can trigger this situation. It's recommended to regularly check the battery voltage with a multimeter; a healthy value should stay above 12.6V, and anything below 11.8V is dangerous.
