
The reasons why the auto start-stop system cannot be used may include low battery power or the engine not reaching the normal operating temperature. Additional details are as follows: 1. Low battery power: Many cars are equipped with an auto start-stop system, which can reduce fuel consumption and lower exhaust emissions. The auto start-stop system consumes a significant amount of power, so when the battery power is insufficient, the system cannot function. After driving for a while, the system can resume normal operation. 2. The engine has not reached the normal operating temperature: Most engine wear occurs during cold starts. During a cold start, the engine oil has not yet reached the surfaces of various components, leaving them in a state of dry friction, which causes the most wear inside the engine. Once the engine starts, the oil quickly reaches the surfaces of components that need lubrication and forms an oil film, at which point engine wear is minimal. When the engine has not reached the normal operating temperature, the auto start-stop system will not activate to avoid damaging the engine. Once the engine reaches the normal operating temperature, the oil forms a stable film on component surfaces, and the wear from restarting the engine is very low. Cars equipped with an auto start-stop system have reinforced starters and batteries, so the system does not damage these components.

My car's start-stop system has failed a few times before, and there are quite a few reasons for that. The most common one is insufficient battery power, especially after three or four years of use, when the battery ages and its voltage drops below the standard value. The system automatically disables the start-stop function to protect the electrical components. Environmental factors also play a role: in winter when temperatures drop below freezing, or in summer when they exceed 35 degrees Celsius, the system may temporarily disable the function to prevent engine damage. Other triggers include unstable vehicle speed, excessive air conditioning use, or frequent starts, which can activate the protection mechanism. It's recommended to first check the battery's health and use a multimeter to measure if the voltage is around 12.6V. For daily maintenance, cleaning the sensor dust and allowing the car to warm up for five minutes before starting can improve the success rate.

The auto start-stop malfunction may be caused by battery issues. Long-term usage weakens it, and the system shuts down when voltage drops to a critical point. Dirty sensors or signal interruptions are also common, affected by rainy humidity or engine overheating. Complex vehicle states, such as high electrical loads from headlights or audio systems, can trigger the system to pause automatically to conserve resources. I recommend regular battery testing and replacement if problems are found; minimize use of high-power devices while driving, and turn off the system in unsuitable temperatures. For recurring failures, using an OBD scanner to read trouble codes helps pinpoint issues faster, saving both money and hassle.

The start-stop system may not work due to an aging battery or system setting errors. It is disabled when the battery level falls below the threshold, so check if the voltage meets the standard. Environmental temperature control is also a factor; the system won't start if it's too cold or too hot. Regular maintenance should include monitoring battery lifespan and timely replacement. Restarting the infotainment system may fix minor issues. Maintain smooth driving to reduce frequent start-stop cycles and avoid using high-power electrical devices.


