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Door Ajar Light Stays On

Updated: Apr 28, 2021

You’ve checked every door on your car, and the door ajar light still stays on, brightly lit on your car’s dash. Frustrating, right? Let’s take a look at what this particular sensor does and what can cause it to break.

The door ajar sensor is relatively straightforward in its purpose: it recognizes when a door on your vehicle is open and alerts your car’s ECU, or electronic control unit. It then lights up an icon on your car’s dash, letting you know a door is open. The door ajar icon is supposed to turn off once the open door has been closed securely.

But what happens if the door ajar light stays on?

Why Your Door Ajar Light Stays On

Depending on the type of vehicle you have, your door ajar light can come on for any number of reasons:

  1. An electrical short in the dome light

  2. An electrical short in the anti-theft system

  3. A door switch stuck in the “open” position

  4. Exposed wires

  5. An electrical short in any of the door switches

Although the most common causes are electrical, they can be mechanical as well. And for this reason, it’s a good idea that when you have one of these sensors coming on that you diagnose the issue right away—either on your own or by bringing your vehicle into your local auto-repair mechanic.

Why This Problem Should be Fixed ASAP

When your car’s ECU believes a door on the vehicle is open, it can do a number of things:

  1. Prohibit the key fob from locking the doors, making it unsafe to park in any public place Cause a safety hazard by not allowing the doors to be locked while the vehicle is in motion – especially a problem if you have curious young children in the back seat

  2. Leave interior dome lights on which can lead to a drained battery

Why Trust Hillmuth Auto Care with Your Auto Repair Needs

  1. We are a full-service Maryland auto service and repair business working on all makes and models of cars and trucks.

  2. We have convenient locations in Columbia, Clarksville, Glenwood, and Gaithersburg.

  3. We offer a 36-month, 36,000 mile Nationwide Warranty on parts and labor from the original repair date and mileage.

  4. We make our services more affordable to our customers with money-saving coupons.

  5. Customers can access our Car Owner’s Tool Center enabling them to check repair history and get maintenance reminders.

Contact us to schedule service on your vehicle at Hillmuth Auto Care today!

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