The Mystery Bubble Finally Bursts


CARS.COM — You’ve probably seen the dashboard bubble. It’s a tiny plastic dome mounted near the bottom of the windshield. Many late-model cars have it, including Chevrolets. The Chevy Impala is one notable car that tends to have this mysterious feature. On our curiosity meter, the dashboard bubble ranks somewhere near whether this morning’s cup of Starbucks was “fair trade” or, um, unfair trade.

It’s a nagging sort of curiosity. Is it a signal point for remote keyless entry? Does it facilitate better radio reception? Does it have something to do with the engine or transmission? Does fair trade brew taste any better than the normal stuff? We checked it out (the bubble, that is — we’ll follow up on that flavor test some other time).

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Turns out the mystery bubble is a sunlight sensor, according to spokesmen from Chevrolet and Honda. It can actuate a vehicle’s daytime running lamps, signal the instrument panel to illuminate or even regulate climate control, depending on the vehicle. So while it has nothing to do with the engine, it is still a pretty handy feature. 

We did a little more digging to learn more about how exactly an ambient sensor works in an Impala or another car. Many newer vehicles feature automatic headlights that turn on when it gets dark and during inclement weather. When this sensor senses darkness, the lights come on. The sensor is designed to help drivers see while improving the efficiency of headlights. In short, Chevy uses this “bubble” in the Impala and other vehicles to help keep you safe and make your headlights more efficient. 

Does that mean a well-placed obstruction could manipulate the system into thinking it was nighttime? Said Chevy spokesman Travis Parman: “I think that would be a great thing for you to test out.”

We’ll get right on it – as soon as we finish our coffee investigation.

Does the Bubble Ever Need to Be Replaced? 

If you drive an Impala or another Chevrolet vehicle with an ambient light sensor “bubble,” there are a couple of instances in which you may need to replace it. Because it is located in close proximity to your windshield, it may not work properly if your windshield suffers a large crack or chip. Sometimes the sensor may also stop working spontaneously. When this occurs, your car or truck may no longer be able to tell whether it is day or night. As such, the automatic features will fail. 

Do you drive a Chevrolet Impala or another vehicle with one of these bubbles? Have you ever noticed it before?’s Editorial department is your source for automotive news and reviews. In line with’s long-standing ethics policy, editors and reviewers don’t accept gifts or free trips from automakers. The Editorial department is independent of’s advertising, sales and sponsored content departments.

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