How to Avoid an Interlock Device Violation

If you are convicted of a DUI in Florida, the judge may impose a penalty that includes installing an Ignition Interlock Device (IID) on your vehicle. The IID is essentially a breathalyzer attached to your car’s ignition switch. The device will prevent you from starting your car until you blow into the IID’s breath sample collection tube. If your breath sample does not exceed the preset alcohol measurement, you will be able to start and drive the vehicle. If you do fail the breathalyzer, then you will be unable to start the car until later when another breath sample will be measured. 


Living with an IID installed in your vehicle can be more difficult than it might seem because the system can notify the Department of Highway Safety and Motor Vehicles that you are in violation of the IID program. As experienced DUI defense lawyers working for many years in Pinellas and Hillsborough Counties, the Stechschulte Nell law firm wants you to have all the information you need if you must drive with an IID. If you receive notice of a violation, you can contact our office for help. 



When Will an Ignition Interlock Device be Required? 


Under Florida law, drivers who are convicted of particular DUI offenses will be required to drive only a vehicle with an IID installed to prevent anyone from driving the vehicle whose blood/breath alcohol content (BAC) level measures 0.025 or higher. The 0.025 level is typical, but a judge may order that a lower IID alcohol preset level be entered to prevent certain drivers from any measurable alcohol. 

The convictions that will trigger the IID requirement include these: 


1st Conviction  May be court ordered 
1st Conv. w/ BAC 0.15 or more or minor in the car  At least 6 months 
2nd Conv.  At least 1 year 
2nd Conv. with BAC 0.15 or higher or minor in the car  At least 2 years 
3rd Conviction  At least 2 years 
4 or More Conv. if granted hardship license  At least 5 years 

Florida Office of Inspector General Audit Report 201819-02 


How Does the IID Work? 


If you are ordered to install an IID as a condition of your license to drive a vehicle in Florida, you will have to pay for the equipment to be installed in your car and to pay a monthly lease fee to the company that operates and monitors the program.  


A driver is required to provide the first breath sample when they start the car. If the test shows a BAC level lower than the trigger threshold level, the driver will be able to proceed. The next event will be the “rolling test” which is a second or subsequent test that the driver will need to provide between 10 and 20 minutes later than the first one. 


The follow-up “rolling retests” are conducted to ensure that the driver has not increased their alcohol intake after they gave the first breath sample. The rolling tests will continue periodically throughout the course of extended driving times. 


What Happens When You Fail a Rolling Retest? 


If a driver provides a breath sample to the IID during a rolling retest with a higher BAC level than the preset threshold or if they fail to provide a sample within 7 minutes of the flashing signal indicating they need to submit a retest sample, then the IID will trigger the vehicle to  


  • flash its headlights, 
  • blow the vehicle horn, 
  • activate the vehicle siren. 


The purpose of the flashing lights, horns, and sirens is to attract the attention of the police and to become so irritating that the driver pulls over and turns the ignition off. The ignition will lock and prevent any restart for a predesignated period. 


The IID will transmit the failed breath test to the IID contract company which will notify the Florida DHSMV of the violation.  


Other IID Violations  


The IID will report the following events as violations: 


  • 2 failed breath tests at the initial start-up of the vehicle. Why 2? Because the driver attempted to drive again after being rejected for an elevated BAC level. 
  • Any refusal to submit a rolling retest will count as a missed test (presumed to be due to the driver’s fear of having a high BAC level detected) 
  • Any failed rolling retest 
  • Any IID power interruption (presumed to be the result of unauthorized tampering) 
  • Any other tampering with the IID equipment (including attempts to have another person blow) 
  • Providing a breath sample to an IID on behalf of the convicted offender to assist them in operating an IID-equipped vehicle 
  • Lending a non-IID-equipped vehicle to a person you know to be restricted to driving only IID-equipped vehicles. 


Penalties for these violations can include new criminal charges, extended periods of license revocation, extended periods of IID requirements, vehicle impounding, and fines between $250 and $500 for each violation plus additional fees and costs including fees related to follow-up meeting appointments.  


Avoiding IID Violations  


Now that you know how an IID system works and what will be considered a violation, let’s look at how to avoid IID violations, including incorrect reports of violations: 


Power Interruptions: The power to an IID should not usually be a problem unless the car is being serviced at a garage where the battery needed to be disconnected. If you are experiencing any electrical issues with the vehicle, notify the IID monitoring agent immediately and get the problem documented and date stamped.  


If you are scheduling any repair work or leaving the car at a garage, notify the IID monitoring agent and have that fact confirmed by your mechanic. Otherwise, an unexplained or undocumented power cut will be considered a tampering violation. 


False Positive Breath Tests at Start-up or Rolling Retests 


IID devices are sensitive instruments designed to detect and measure the presence of certain volatiles which are substances that are easily vaporized at relatively low temperatures, like alcohol. But other foods, drinks, and other substances also contain similar volatiles or components that can be identified as alcohol on some instruments and must be avoided when using an IID.: 


  • Mouthwash — many types of mouthwash contain alcohol. Either use a non-alcohol mouthwash or make sure you rinse thoroughly and wait for a sufficient period after using it before attempting to operate the IID. 
  • Breath mints — Altoids, Mentos, or other mints and breath fresheners can have an effect similar to mouthwash when using an IID. You should also avoid strong chewing gum, like Dentyne or other cinnamon-flavored gums and candies. 


Intentional conduct like operating a car without an IID in violation of a court order is a matter of choice and is within your control. Having another person blow a breath sample into an IID to get a car started is also not going to benefit a driver who is then required to provide another breath sample during the rolling retests. Of course, if you want another person to drive the car, they would simply provide each of the required samples.  


Learn More > What You Need to Know About Interlock Devices in Florida  


Get Help with Your IID Violations 


If you are required to use an IID in your vehicle and you are accused of violating the terms of the IID program, contact us at Stechschulte Nell, Attorneys at Law in Tampa. We have extensive experience defending all DUI, Refusal, and related charges, including all allegations of IID violations. Call us for a case review today at 813-280-1244.  

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