How to Avoid an Interlock Device Violation

February 20, 2019

If you have recently been charged with a DUI, you know that there are serious consequences coming your way. Although sentencing differs according to the severity of the DUI and the state of the violation, most common penalties include fines, court fees, license revocation, jail time for some, and in 32 states, the installation of an ignition interlock device for even first-time offenders.

For those that are required to purchase, install, and maintain an interlock device in order to drive, adhering to the court-mandated rules attached to these devices will help you pay your dues and get back into society’s good graces. Violating the rules of your court-mandated interlock device can have serious consequences, either extending your current penalties or adding new ones. A DUI is a serious offense in and of itself, you don’t want to add to it. Committing an interlock device violation is never worth it.

So, if you want to avoid committing an interlock device violation, you first need to know what they are and how they work.

Interlock Devices – How They Function

Interlock devices, also known as car breathalyzers, are designed to prevent high-risk drivers from starting their cars and driving under the influence. A 2017 Mothers Against Drunk Study, found that ignition interlocks had been responsible for stopping more than 2.3 million attempts by motorists to drive drunk, likely saving thousands of innocent lives in the process. Thanks to this success, they are now required by 32 states for first time DUI offenders and mandatory in the other states for repeat offenders or drivers who blew above a specific BAC.

A driver with an interlock system installed in their vehicle is required to regularly perform two actions in order to satisfy the requirements of the breathalyzer:

  1. Take an initial breath sample
  2. Perform a rolling retest

The Initial Breath Sample

Car breathalyzers are wired into your car’s ignition system. When you enter your car, you have to breathe into the ignition interlock device in order to turn on the engine and get going. The driver will blow, hum, or suck a specific pattern so that it might gather the necessary data, (although in the case of Low Cost Interlocks, our devices only require a simple 3-second exhalation.)

If the device registers a blood alcohol concentration (BAC) level higher than the set limit, it will stop any attempt to start the vehicle by interfering with the signal between the starter and the ignition. Even cars with smart ignition or push-to-start will be unable to go until the device registers a valid breath sample.

The Rolling Retest

Even if you pass the initial breath sample and are able to start your vehicle, the ignition interlock device will intermittently request an additional breath sample from you while you are driving. This is referred to as a rolling retest and was added as a requirement in order to prevent those who managed to cheat the initial breath sample, say by having a different sober person provide the breath sample in order to pass and go.

The rolling retest is performed exactly the same as the first test, but the only distinction is that you have already started your drive. Drivers with an interlock device should expect the rolling retest to occur within the first ten minutes of their drive as a result of the state mandate. If the random rolling retest on the device is triggered, it will:

  • Signal you by flashing or beeping
  • Request a new test
  • Give you roughly seven minutes to take the test

Failure to Take or Pass the Test

If you do not give a breath sample in the seven-minute window or if you fail the test, the device will do the following:

  • Record the test as a failure or missed test, either of which can be considered violations
  • Flash your car’s lights
  • Honk your car’s horn
  • Set off the device’s internal siren, which is less than pleasant

These things remain in accordance with state regulations and are meant to both annoy the driver and signal to any police in the area to pull you over. The car will never just shut off since that would be extremely dangerous. However, if you wish these signals to stop, you will have to pull over and submit an additional breath sample. Those that pass will be free to continue driving, but those that fail will have their car locked down by the interlock device for a pre-determined period of time.

Now that you are aware of how the device works, we can discuss the most common interlock device violations and how to avoid them.

How to Avoid an Interlock Device Violation

There are several ways a person can be given an interlock device violation. They include:


Tamper/circumvent violations happens when:

  • The device notes a power disconnect;
  • The device notes a power failure to the vehicle; or
  • The interlock device company reports that their device has been damaged, tampered with, or jerry-rigged.

As you might imagine, the first two violations can easily occur if a mechanic is working on the car, or if the battery is switched out or simply dies. Unfortunately, all too often drivers who are upholding the rules and conditions of their interlock device are erroneously charged with a tamper/circumvent violation.

Such honest mistakes can lead to a license revocation or extend the period that an interlock device is required to be in the car. To protect yourself and avoid a tamper/circumvent violation do the following things:

  • Never mess with the device, even if it looks broken or doesn’t seem to be working. In such cases, contact Low Cost Interlock or drive to one of our various locations to have the device looked at.
  • If you need repair work done, document everything, take pictures, and keep receipts.
    • Make sure that your receipts are official and have clear dates and times of repair which coincide with the power failure.
    • Ask your mechanic to contact Low Cost Interlock and to notify us about the expected power failure disconnect.
  • Contact Us to make sure that we are aware of the fact that work is being done on your car.
    • Check that your mechanic has notified us about the expected power failure.
    • Check that we have notified the state in written form explaining the power failure.

Although this may seem like a major hassle, it is better to be safe than sorry, especially since this is one of the violations that often occurs as a result of oversight rather than a driver’s mistake.

Failed Tests

Even people with the best of intentions can have their judgment skewed by alcohol. Drivers with an interlock device may still be tempted to drink just enough that they still manage to pass their breath test and drive. Most devices will record a failed test if you have even a .02 BAC and multiple failed tests can result in violations and imposed penalties.  

If you attempt to drive while drunk and wind up blowing a BAC over .08, the device will register this as both a failure and a violation. If you violate this two or more times, most state DMVs can and will extend your ignition interlock requirements for another half year and possibly impose additional fines or penalties.  

If you want to avoid an interlock device failed test violation, never ever drink and then drive.

There is no such thing as a “False” Positive

Simply put, Ignition Interlocks are made to read all alcohol. Certain foods contain small doses of alcohol or sugar that convert to trace amounts of alcohol during digestion. In some instances, this can cause a positive breath test that registers as a failure (the device is working properly and detecting alcohol).

Mouthwash is the most common culprit for positive tests seeing as it contains high concentrations of alcohol. If you regularly use mouthwash, make sure to rinse it out with water and then give yourself at least 15 minutes for that to dissipate.

Other foods you should be wary of include:

  • Altoids
  • Chocolates
  • Cinnamon rolls or donuts
  • Dentyne or other spicy gums
  • Gummy bears
  • Mints

If you do eat these foods, prior to submitting a breath sample be sure to rinse your mouth out thoroughly with water and then wait a few minutes before you take the breath test.

Having Another Person Blow into Your Ignition Interlock

A person who is caught attempting to undermine their interlock device by having another person blow into the ignition device can face serious legal trouble. Such a violation would be discovered if a person blew so that you could pass the initial test, but then you proceeded to fail the rolling re-test.

If you wish to have someone drive your vehicle, they must blow in the device for the vehicle to start. If that person fails the breath test, it counts as you failing the breath test. According to federal laws, you are wholly responsible for anyone who gets behind the wheel of your vehicle; their violations are your violations.

Driving the Vehicle without an Interlock Installed

Your state will require that you install an ignition interlock by a given date compliant with the penalties of your DUI. If you are pulled over, or do not prove that you have complied with your ignition interlock compulsions, you will likely face far more severe consequences. If you wish to avoid this violation, simply reach out to the specialists at Low Cost Interlock and get the install process going as soon as possible.

Failure to Recalibrate the Device

Many states require that you have your interlock device regularly calibrated. This calibration will typically occur once each month. It ensures that the breath samples are accurate and affords the state and authorities an opportunity to observe your usage records. These reports give detailed breakdowns on drives, failed tests, violations, or power failures. The log can demonstrate the times and dates you’ve used the device, as well as any time you failed to give a sample, or gave a sample that was far too high to drive legally. The authorities have the right to request such logs and impose stiffer sentences if necessary.

If you wish to avoid an interlock device violation for failing to recalibrate the device, simply bring it in as required. If possible, set your next recalibration appointment during your current appointment and create a reminder in your phone so you do not forget.

Interlock Violation Consequences

The penalties for multiple interlock violations will naturally vary on a state-by-state basis, but they can be quite harsh, especially if they believe that you have purposefully tampered with the interlock device. Examples of penalties include:

  • Jail time, especially if tampering with the device
  • Extended license suspension period
  • Complete driver’s license revocation
  • Additional fines
  • Charges for driving on a suspended or revoked license (if you do not install the device)
  • Vehicle impounding
  • Extended interlock device requirements

Get Your Device Installed Today

Ignition interlock devices may be an annoyance, but they keep you and others safe on the road. Driving with restrictions is better than not driving at all, so treat it like the privilege it is. If you want to avoid a device violation, simply:

  • Don’t attempt to drive drunk
  • Don’t tamper with the device
  • Don’t drive without installing an interlock device

Obey the rules of the road and you will not have to worry.

So, if the court has mandated that you get an interlock device installed, do it immediately! Don’t hesitate. Reach out to the knowledgeable professionals at Low Cost Interlock and we’ll get you back on the road in no time at all. We are proud to offer free shipping, installation, and set up for either of our interlock devices. Contact us now to get started!

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