3 Reasons Why You’d Get Locked Out Of Your Ignition Interlock Device

ignition interlock deviceOnce you’ve had an ignition interlock installed in your vehicle for awhile, it becomes fairly routine to use. When you want to start your vehicle, just pick up the interlock device, blow into it, and you’re free to drive as your license provides. But what happens if you get ‘locked out’ or can’t start your car because of your ignition interlock device? It is frustrating, so here are some common reasons and suggested solutions.

Here are 3 reasons why you’d get locked out of your ignition interlock device:


Failed Test

One reason why your ignition interlock device won’t let you start your vehicle is because you have alcohol on your breath. The threshold for the amount of alcohol you can have in your system before driving will vary according to state, but it is ALWAYS lower than .08.  Alcohol from foods (like vanilla extract), mouthwash, toothpaste, even hand sanitizer and windshield wiper fluid all contain alcohol and can impact your reading.  If you fail and you haven’t been drinking, rinse your mouth with water, open the car windows to dissipate any environmental alcohol and try again when prompted by the device.  Keep in mind that if you were drinking the night before, your BAC may still be above the state-allowed limit to use an interlock equipped vehicle.   While driving, if you are required by the state to take a “rolling re-test” make sure to avoid drinking, eating or smoking while driving.  Don’t vape.  Changes to your usual activities and incorporating the interlock take time and patience.   You will get used to it.

Missed Service Appointment

Once you install your ignition interlock device, you’ll need to attend regular service appointments. Intervals vary between 30, 60 and 90 days.  We send a reminder email to you prior to your scheduled appointment.  The best plan is to make your next appointment at the time of your current one.  A Guardian Interlock device will give you daily reminders of when your service appointment will be, and if you miss your appointment, your vehicle will be put in permanent lockout. At that point you’ll have to have it towed into the service center for a lockout reset, so be sure to always attend your service appointments.

Changes were made to the vehicle or the device

If you try to remove or disable the device yourself, you could be locked out of your vehicle. If you need to work on your car, including replacing a battery or getting an oil change, call us FIRST.  You will need a mechanic’s affidavit for the state and a special code for the mechanic to bypass the interlock.  Not doing these things before you service your car will read as an attempt to circumvent it.   That’s a state violation.


  1. My interlock device went into permanent lockout. When I finally got to the service center I was advised that the reason was that I failed to “re-test”. I did not miss a re-test and am very concerned that this will happen again. I had to miss another full morning of work. The anxiety of having the interlock device is overwhelming. When the technician told me that I failed to re-test there was no point in defending myself because she said that the results are recorded. Is it possible to have a mal-functioning device? Is it possible to switch out a handset for another one? Also, the days before service do not countdown consecutively. My device went from 29 days to service to 19. What is the reason for this? I will never drink and drive again. I am so overwhelmed with the consequences from doing so. Has anyone had the experience of a malfunctioning handset or any other interlock component?


  2. Charles Hickman says:

    We’re sorry you’re having problems with your interlock. If the device itself is not functioning correctly, it can certainly be replaced. Just call our service line, (1-800-499-0994 option 2), and we’ll help you out.

  3. What is a device lockout? I used my inhaler and it said blow longer but I was short of breath then it said blow harder then it said suck air out. Then it did its 30 min lock out time. Reset and siad blow again I did said test failed and said device lock out in 3 days.

  4. Shelly Wutke says:

    Thank you for your comment. When a device lockout occurs, your ignition interlock will temporarily not operate due to too many fails or aborts. For more information on how the interlock works, please see our FAQ

  5. Vickie Reese says:

    As soon as I order my recalibration with intoxalock my device starts counting down with 2 days when I usually order a week to 10 days in advance. Is this a malfunction? I’m afraid to wait till closer to my actual date for fear of being locked out. Please help me with this

  6. Charles Hickman says:

    Please call one of the Guardian representatives at 800-499-0994 and they will help with this issue. Thank you.

  7. Anon Ymous says:

    A friend said his interlock device returned a tamper reading and claims it it was fine until his battery died for however many days and after getting it replaced, couldn’t start.

    He has a 2002 Chevy avalanche and also has an engine code reader witch is only showing an oxygen and to replace the knock sensor

    I will be updating the software to the reader but, if it still doesn’t read anything new, is there any way to pull codes like that the battery had been removed or what have you?

    Because he is not allowed to drive now because this false interlock report.

    Thank you for any help

  8. Charles Hickman says:

    Service questions should be directed to customer service at 800-499-0994. They can get the customer in touch with a service technician.

  9. Jenny saldivar says:

    Can you pull my blowing record anytime you want or only when it gets downloaded to the computer for that month?

  10. Charles Hickman says:

    Data must be downloaded in order to be sent to monitoring authorities.

  11. I’ve had my interlock for 1 day and I’ve already gotten temp locked 3 times . I takes me 4 ties every time I need to start my car . Every time is the same way I blew the first . Am I doing something wrong or could it be malfunctioning???

  12. Editorial Staff says:

    Hi Aaron,
    I’ve forwarded your information along to our customer service team. You can also check out our Training Videos.

  13. Editorial Staff says:

    Please have him call our customer service center at 800-499-0994.

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