How Do Interlock Ignition Devices Work?

Unless you have previous experience with a driving under the influence (DUI) arrest or know someone who has, you probably have no idea how inconvenient and limiting an interlock ignition device (IID) can be.

The device attaches to your vehicle's ignition and screens you for blood alcohol content when you blow into a handheld sensor unit. Every time you want to drive the car, you must blow into the device and pass the test. If you fail the blood alcohol test, the engine does not start. Rolling tests or retests are also part of an IID's function. The device requires drivers to blow into the device at random times while driving. If drivers fail to take or pass the rolling test, the device issues a warning alarm, such as the horn honking or lights flashing, until you turn off the ignition. To restart the car, you must pass the test. The device also keeps a log of times when you fail to perform the test or your blood alcohol content exceeds the preset acceptable range.

An Arizona State Senate brief issued in August 2012 explains state laws involved with an IID. For example, to obtain a restricted driver license after the initial DUI, which comes with a 90-day license revocation, you must install a certified IID on your vehicle. The ignition interlock restricted license is for first, second and extreme DUI offenders. Along with requiring an IID, the restricted license gives you limited driving privileges, such as driving to your place of work and residence. Depending on the type of conviction and your tested alcohol level at that time, you may be required to use the IID for 12, 18 or 24 months.

Ideally you can avoid DUI conviction altogether by working with an experienced DUI lawyer. Rely on a law firm with extensive criminal defense experience and an attorney who is dedicated to helping you beat the charges.


Keep a Firm Grip on Your Freedom.
The Battle Is Just Beginning.

    • Please enter your name.
    • This isn't a valid phone number.
      Please enter your phone number.
    • This isn't a valid email address.
      Please enter your email address.
    • Please make a selection.
    • Please enter a message.
Put Us On Your Side