Is It Normal for the Car Malfunction Light to Disappear After Ignition?

[Beau]

It is normal for the car malfunction light to disappear after ignition, and the reasons are as follows: 1. After turning on the ignition switch, the vehicle's various system computers will perform a self-check. 2. If no fault is detected in the system after the self-check, the malfunction light for that system will not illuminate after starting the engine. Car malfunction lights can be divided into three types: 1. Indicator type: Used to explain some basic conditions of the vehicle, indicating the current working state of the vehicle, making it easier to understand the various functions and status of the vehicle. (e.g., lighting system indicator, water temperature indicator, fuel level indicator) 2. Prompt type: Used to indicate that the current state of the vehicle is abnormal or the operation is incorrect. (e.g., seat belt reminder light, door open reminder light) 3. Warning type: Indicates that the vehicle has a fault and requires repair. (e.g., engine malfunction light, oil light)

[JordanDella]

This issue is common in cars. From my driving experience, it's normal for warning lights, including the engine light, to illuminate for a few seconds during startup as part of the self-check process. The vehicle's computer system quickly inspects key components like the engine, ABS, or airbags after ignition. If no issues are found, the lights turn off automatically—similar to your phone's system check before booting up. However, if a light stays on continuously or flashes, it may indicate a problem, such as a sensor malfunction or emission system anomaly, and should be checked promptly. Most cars I've driven behave this way—lights turning off after ignition is nothing to worry about. But if they remain on abnormally, don't ignore it; use an OBD scanner to check the trouble codes promptly.

[SanConnor]

As an automotive enthusiast, I've learned that the brief illumination of warning lights upon vehicle startup is a normal part of the system self-check. The ECU controller runs diagnostic procedures to confirm all components are functioning properly before turning off the indicators. Conversely, if a light remains on, it signals potential issues like a faulty oxygen sensor or fuel system problems that require professional diagnostic tools. During maintenance, a technician once explained this process is designed to ensure safe vehicle operation - temporary light activation can be ignored, but persistent warning lights need troubleshooting to prevent performance impacts.

[SanLandon]

I had this question when I first started driving. Don't panic when those red and yellow lights turn on briefly and then go off after starting the car—it's just the vehicle's self-check process, a normal function. For example, if the engine light goes off, it means the check passed without issues. If it doesn't go off, there might be a minor problem like a loose wire, so just drive to a shop to get it checked. Don't delay to avoid turning a small issue into a big one that could affect your driving.