Debunking False Positive Readings with Tennessee Ignition Interlock Devices for DUI

debunking-false-positive-readings-with-tennessee-ignition-interlock-devices-for-duiTennessee has required ignition interlock devices for those convicted of DUI with a BAC of 0.08 percent or greater since 2013, and then in July 2016 a new law went into effect that, “Revises the interlock law to make an ignition interlock device required unless the judge makes specific findings that the person seeking the restricted license does not need the device.” (DUI offenses HB1843 SB2065)

The new law also establishes penalties for devices that have been tampered with or removed from the vehicle. Mothers Against Drunk Driving has sponsored research that shows how ignition interlock devices are effective at reducing drunk driving because they change the drunk driver’s behavior even after the device is no longer in the vehicle.

The purpose of the ignition interlock device is to detect the presence of a group of methyl compounds including ethyl alcohol in the breath of the driver before they start their vehicle. The technology is designed to be very sensitive to the chemistry of the human body to rule out the possibility of a true “false positive” reading. If you have been drinking alcohol and you blow into the IID, that positive reading will be reported to our monitoring agency.

An ignition interlock device gets wired into the ignition system of the offender’s vehicle. To start the vehicle, the driver must first blow into the device to measure their blood alcohol concentration. The ignition interlock device has a camera that snaps a photo every time the breathalyzer is used, so that no one else can blow into the device to start a vehicle on the driver’s behalf. First time DUI offenders must use the IID for six months. The device costs between $50 and $200 and users pay a monthly maintenance fee ranging between $50 and $100 per month.

What if my ignition interlock device gives a false positive reading?

If you have been sentenced to install and use an ignition interlock device, every time you want to travel somewhere in your vehicle, you must stop and blow into the device in on order for it to start, and then at some point on the drive, you must blow into it again for the vehicle to keep driving.

Regardless of why your test failed, you will be given another chance in a few minutes to test again. That way, if it was a false positive triggered by the presence of mouthwash or spicy food, it should dissipate in a few minutes and you should be able to blow a clean test and start your car and be on your way. If you are a diabetic, and your blood sugar is low it could also trigger a false positive. A good rule of thumb to follow when you have an IID installed is to wait 15 or 20 minutes after you eat before you try to drive, especially if you have eaten spicy foods or freshly baked bread. If you are a diabetic, eat something and then wait a few minutes before you blow into an ignition interlock device and drive.

If the device did malfunction and falsely detect the presence of alcohol in your system when you had not been drinking, it is in your best interest to continue with the retests until you blow a clean test so that you can explain what happened to your monitoring agency.

If you have been convicted of DUI in Tennessee and you get a false positive reading, you will need the aggressive representation of an experienced, Franklin DUI attorney from the Low Offices of Adrian H. Altshuler & Associates. We will protect your rights and your reputation as you move through the judicial system. You may contact us or call 615-977-9370 to schedule a consultation. From our offices in Franklin, Columbia and Brentwood, we serve clients throughout Tennessee.