What Happens If I Accidentally Fail My Ignition Interlock Test?

If you have a newly installed ignition interlock device installed on your vehicle, you have a lot of questions. The technician who installed the device probably gave you a run through of how the whole system works, and gave you the operating manual, but you’re probably wondering what will happen if you accidentally fail your ignition interlock test.

And it is possible to fail your ignition interlock test even if you haven’t consumed any alcoholic beverages.

How an Ignition Interlock Device Works

First, it helps to know exactly how the ignition interlock device (IID) works. The device includes a handheld device with a mouthpiece that you blow into, and an Electrical Control Unit (ECU) that is connected to your vehicle’s electrical system. The ignition interlock device program requires you to blow into the device before you can start the vehicle. If your breath alcohol concentration (BAC) is higher than the pre-programmed level, (generally .02 or .025) the device prevents the engine from starting.

To make sure that you haven’t had any alcohol since you started your vehicle, the IID is programmed to require that you give random samples during your drive. These random samples are required by law. The legal requirements in your state or county will determine how much time elapses between retests. Your program requirements may also vary depending on whether your DUI was a first offense.

There’s No Such Thing as a False Positive for Alcohol

An ALCOLOCK ignition interlock device, or IID, is a highly calibrated and highly accurate piece of equipment which uses fuel cell technology. Our interlock devices have a range of measurement from 0 to 1.00 mg/L and provide results with an accuracy of plus or minus 0.02 at 0.20 mg/L. In other words, they’re incredibly accurate. So if you have the tiniest bit of alcohol on your breath, an interlock device will detect it, flash a message or beep, indicating that you failed the test. As a result, the IID will not let you start your vehicle.

But Wait! I Haven’t Had Anything to Drink, and It Says I Failed the Test!

So we did say ignition interlock devices are highly sensitive to alcohol. Even if you haven’t consumed an alcoholic beverage, there may still be alcohol on your breath. For example, if you use mouthwash with even the tiniest bit of alcohol in it, the IID will detect this alcohol content on your breath. If you haven’t been drinking, but you used mouthwash, ALCOLOCK recommends you swish their mouth with water. The alcohol from the mouthwash will quickly dissipate with the water. The same thing goes for breath spray. Wait a few minutes, and then take the test again. Your best option is not to use these products while you are in the interlock device program.

Similarly, if you eat a meal where alcohol was cooked into the food, such as pasta with Vodka sauce, or a rum cake, even though the alcohol was supposed to have burned off in cooking, you may still fail the ignition interlock device test if you blow into the device right after a meal. We suggest making sure your mouth is clear of any food particles, and waiting at least 15 minutes after a meal before taking the test.

And according to a study published in the Journal of Analytical Toxicology, consuming energy drinks like Monster or Red Bull can result in enough alcohol in your system to cause you to fail the test.

Each state has different ignition interlock device laws regarding how many times in a row you can fail the breath test before the vehicle locks you out entirely, so it’s best to avoid these accidental test failures. The devices monitor your success / failure rate and those results are transmitted monthly to the person or agency monitoring your progress, such as the DMV or your probation officer. Failing the test can result in increased penalties.

What to Do if You Accidentally Fail Your Ignition Interlock Test

In addition to the steps we described above, you may want to contact the person or agency monitoring your progress in the program to let them know what happened. You may also wish to contact your DUI lawyer.

We’re With You On the Way Back

ALCOLOCK is dedicated to helping you succeed. We want to make it easy for you to comply with the terms of your DUI/DWI ignition interlock program while you work to get your driver’s license reinstated and get your full driving privileges back. Call 866-700-9300 with questions, or use our contact form to schedule an installation.

Skip to toolbar