How Does an Ignition Interlock Device (IID) Work?

By San Diego Attorney on September 13, 2013

If you have been convicted of driving under the influence (DUI) in the state of California, you may soon be asked to install an ignition interlock device in your vehicle. This device, which is roughly the size of a cell phone, will be attached to your dashboard and wired to your ignition. Once the mechanism has been activated, you will not be able to start your engine until a breath sample has been submitted—the purpose of which is to keep you from driving while under the influence of alcohol. If your calculated blood-alcohol concentration (BAC) is greater than the pre-programmed amount, your car will not start. The device will also record a violation. To ensure that it is, in fact, you who is breathing into the device, it will also ask you to submit additional breath samples at random intervals.

If, at any point, the ignition interlock device records an excessive BAC level, you will be warned to pull over until the engine has been turned off. Since the device cannot turn off your vehicle’s engine without putting you in danger, it has been programmed to start up an alarm (i.e. lights flashing, horn honking) until you are able to safely pull over and stop the vehicle. The device will also log the event as a violation. While some people think that there are ways to “cheat the system,” ignition interlock device manufacturers have incorporated a number of safeguards. For example, the IID will abort phony breath samples (i.e. air from a balloon), the IID will continue to function if the battery is disconnected, the IID will log a violation if the vehicle is left running and a sample is not provided, etc.

If someone were to help you circumvent the restrictions of the IID (i.e. by providing a breath sample in place of yours), they could face fines and/or jail time, as well. For this reason, it may be in your best interest to simply abide by the conditions that the court has set out for you. If you have not yet been convicted of a DUI offense, one way to avoid the aftermath of a conviction would be to enlist the help of a San Diego criminal defense attorney from JD Law. With more than 30 years of experience, our Certified Criminal Defense Specialist knows what it takes to successfully fight a drunk driving conviction. All you need to do is contact our firm today at (760) 630-2000 to learn more about how we can help.