Does being able to lock the car prove that the engine is off?
4 Answers
Being able to lock the car proves that the engine is off. When the vehicle is not turned off, the doors cannot be locked. Even if some models can lock the doors without turning off the engine, they will automatically shut down after locking. Of course, this is also for safety reasons. Even vehicles with one-button start function cannot lock the doors without turning off the engine. Additional information: Reason: This is for safety considerations. After parking, the vehicle remains in one position for a long time. As exhaust gases accumulate, they are highly likely to enter the car through the air intake (since the vehicle is not completely sealed, even with the internal circulation on, it is unavoidable). If someone is locked inside the car, the consequences could be unimaginable. Precautions: Check the tachometer and display screen. Before getting out of the car, see if the display screen has turned off and gone black. Check if the tachometer has returned to zero. This is a conventional method to develop as a habit. However, sometimes with many people in the car, answering phone calls, or being in a hurry to get out, this habit might be overlooked.
I've been driving since the 1990s, and I remember cars back then were all old models where you had to pull out the key after turning off the engine to lock the doors, so locking the car indeed meant the engine was off. Now that I drive more, I've noticed this rule has changed with newer cars. Keyless systems have complicated things—some high-end cars will lock the doors with just a press of the button if you forget to turn off the engine, as long as the key is on you, while the car is still running. This is quite dangerous. Once, my neighbor’s car was left running like this for a long time, wasting gas and polluting the air. So I always check the engine light or listen for sounds, not relying solely on locking the car to judge if the engine is off. Develop a habit: after parking, check if there’s exhaust coming from the tailpipe or feel if the hood is warm—these small actions can prevent big troubles.
As an automotive electronics enthusiast, I've studied modern car locking systems and found that locking the car doesn't necessarily mean the engine is off. Most conventional cars are designed so that the remote can only lock the car when the engine is turned off and the key is removed, which serves as basic proof. However, high-tech models are different—doors can be locked even while the engine is running as long as the smart key is within the sensing range. This is a security loophole that manufacturers should address. I've tried a friend's plug-in hybrid, which has an auto start-stop feature. Locking the car at idle is fine, but it might misjudge after restarting. My advice is to check the dashboard: if the RPM returns to zero or warning lights are on, then the engine is truly off. For safety, it's best to use the mechanical key to lock the car rather than relying on electronics.
I often drive to work and used to lock the car and leave immediately. But once I forgot to turn off the engine and locked it directly, resulting in the car idling in the parking lot for hours, which not only wasted fuel but was also very dangerous. Since then, I've learned that locking the car doesn't necessarily mean the engine is off, especially when the auto start-stop is active during city traffic congestion. Now I make sure to park the car, shift to neutral, pull the handbrake, and confirm the engine is silent before locking the door. A simple practice is to develop a double-check habit: look at the tachometer or smell the exhaust, don't be lazy. This has saved me a lot on repair costs.
