What Is An Ignition Interlock Device (IID)?

An ignition interlock device (IID) is a small breathalyzer that is installed on the steering column of your automobile, and also any vehicles you own and have access to operate. These devices are typically installed after a judge has ordered it to be installed in your vehicle when on probation for a California DUI.

The device is roughly the size of a cell phone. It prevents you from starting the vehicle without having first blown into the device and providing an alcohol-free breath sample. Once the vehicle is started, it will ask for random samplings after approximately 10 to 15 minutes and then again at 45 minute intervals.

When the vehicle is being operated, you will have adequate time to pull over and provide a breath sample; you will have several minutes to submit your sample. Some devices cause the vehicle to stop operating and then the horn begins to honk. If you should fail the breath test at any of the scheduled intervals at which you must provide a breath sample, the IID will indicate that you failed.sThe failure will then be reported to the court that ordered the installation of the device.

To prevent others from providing a breath sample for you, the IID requires a specific breath pattern and has a cord that will not reach the passenger or the rear seats. Needless to say, it is a crime to get someone to provide a breath sample for you or to in any way tamper with or attempt to disconnect the IID.

Any individual who has been convicted of a DUI in California can be ordered to have an IID installed. Generally speaking, a judge will not order the installation of an IID for first time DUI offenders, unless the BAC is at or higher than .15 or if you refused a breath or blood test. However, beginning in July 2010 every person convicted of a first time misdemeanor DUI in Los Angeles, Alameda, Tulare and Sacramento counties must have an IID installed, usually for six months or less. If the DUI resulted in an injury, you may have an IID for one full year.

Repeat offenders will be ordered to have an IID installed for one full year for a second DUI conviction, two years for a third and three years for a fourth.

All approved IID installation facilities must be registered and issued a license by the Bureau of Automotive Repairs. Installation charges are roughly $100, in addition to approximately $75 per month for monitoring fees. You are also responsible for all maintenance and calibration expenses. The installation does not damage your vehicle and can be removed following the completion of your DUI probation.


If you or a family member has been charged with a DUI, it is in your best interest to get advice from a California criminal defense attorney with a proven track record in handling DUI cases.

Ronald N. Hoffman, with Hoffman & Associates, has been successfully defending the rights of clients in Los Angeles and San Diego for over 30 years. We also serve the San Fernando Valley, including Van Nuys, San Fernando, Glendale, Burbank and Pasadena. Let our experience help you through this difficult time.

Contact us at (323) 655-3900 for a no obligation initial consultation about your situation.

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