What are the reasons why the auto start-stop system is not working?

[MorganDella]

The reasons why the auto start-stop system is not working are: 1. The engine has not yet warmed up when the car is just started, and the water temperature has not risen; 2. In cold weather, the outside temperature is below 5 degrees Celsius; 3. The battery power is insufficient. The auto start-stop system is a set of systems that automatically shuts off the engine when the vehicle temporarily stops during driving (such as waiting for a red light), and automatically restarts the engine when the car needs to move forward again. The auto start-stop system is achieved by implanting an enhanced motor with idle start-stop function on the traditional engine, so that the engine is completely shut off and does not work when the idle stop conditions are met. When the vehicle needs to start moving forward again, the idle start-stop motor system quickly responds to the driver's start command, quickly starts the engine, and connects instantly, reducing fuel consumption and exhaust emissions.

[DiMia]

Last time when I was driving my friend's car, I noticed the auto start-stop system kept failing. Common causes include an aging battery with insufficient charge—the system detects low voltage and shuts off the function to prevent startup failure. If the engine temperature isn't ideal, such as during a cold start or with the AC on high, the start-stop may be paused to protect components. Also, if there's a high electrical load from accessories like the AC or headlights, the system automatically disables start-stop. Faulty battery sensors or software bugs can also cause malfunctions, similar to a phone app glitch. Road conditions like steep slopes may automatically deactivate start-stop to prevent rollback risks. I suggest first checking the battery charge with a voltmeter; if that's normal, verify the settings to ensure it's enabled. Frequent failures require a mechanic visit to avoid increased fuel consumption. Regular maintenance should focus on battery health to avoid breakdowns on the road.

[MacXavier]

My car's start-stop system has failed a few times, and after checking, I found the battery was the issue. In cold weather, the starting voltage is too low, so the system automatically disables start-stop to prevent failure to start; when the AC is on, the compressor operation also temporarily disables start-stop because the system prioritizes comfort; additionally, if the cabin temperature is set too high, start-stop may be delayed or disabled to protect the engine; aging battery sensors misreporting electrical parameters can also cause problems; frequent short trips that don't fully charge the battery similarly affect the function. I learned that checking battery life during every service is crucial, and it's best to use a simple tool to self-test voltage—it should be above 12 volts to be normal. Ignoring these can lead to higher fuel costs and affect starting safety. Paying attention to driving habits, like avoiding steep slopes, can reduce trouble.

[DanielaDella]

When the auto start-stop doesn't work in a new car, friends say weak battery is the key reason. The system requires sufficient voltage or it deactivates; function also pauses when engine is too cold or overheated; AC operation drawing current may temporarily disable start-stop; some vehicles have manual override buttons that may be accidentally pressed; multiple start protection gets triggered. Recommendation: don't tamper randomly - check settings or do minor voltage tests, visit repair shop immediately if issues are found to prevent system damage affecting driving efficiency. Simply put, the feature deactivates when conditions aren't right.