What you should know about ignition interlock devices

If you have received a conviction for driving while intoxicated, law enforcement may require you to have an ignition interlock device as a way to prevent subsequent convictions for driving while intoxicated.

Another DWI offense could add further fines and increase your driver’s license probation period, so it is critical for you to follow the requirement to the letter. If you anticipate an order to obtain one of these devices, here is what you can expect.

What are ignition interlock devices?

An interlock device is a breath test device installed in the ignition system of your car, according to the Centers for Disease Control and Prevention. To start the vehicle, you must blow into a tube connected to the device. The machine then measures your blood alcohol content level, and if it is below the preset limit, it unlocks the ignition and allows you to start the car.

During the drive, the machine alerts you to enter subsequent breath tests — referred to as rolling retests. If at any time your BAC reaches above the limit, the vehicle will begin to power down.

What do you need to do?

To obtain an interlock device in your vehicle, you will have to go to a registered dealer. After they install your monitor, you must bring your car in for maintenance appointments. The technicians will check your monitor for tampering, re-calibrate if necessary and download information from the system to the database. The monitor records information, including startup attempts, failed attempts, BAC levels and potential tampering.

An ignition interlock device allows you to use your vehicle and get where you need to go, even after you receive a DWI conviction.