Ignition Interlock Device Requirements From a DUI

If you have pled guilty to or have otherwise been convicted of a DUI, the court or DMV may require that you install an ignition interlock device (IID) in your vehicle when your license is reinstated.

Below our DUI lawyers explain how the IID works, installation requirements and other frequently asked questions.

Ignition Interlock Device Overview

Update: SB 1046 has extended the ignition interlock device pilot program to January 1, 2026.

This bill will make an individual whose license has been suspended for driving a motor vehicle when he or she has a certain blood-alcohol concentration and who is eligible for a restricted driver’s license eligible for a restricted driver’s license without serving any period of the suspension if the person meets all other eligibility requirements and the person installs an ignition interlock device.

SB 1046 bill commences January 1, 2019.

The ignition interlock is a device that stops a person from being able to drive their car if they have a measurable amount of alcohol in their system.

The device does this by measuring a person’s breath alcohol level to see if they are registering a level of alcohol consumption.

Pilot Program

Pursuant to a pilot program implemented by the State of California that began in 2011, 4 counties were selected whereby all first-time DUI offenders whose convictions occurred in those counties are required to install the device in all of their vehicles.

On January 1, 2019, the program was extended state-wide to include all California counties1.

How Does An Ignition Interlock Device Work?

This device is installed on the vehicle dashboard and requires you to provide a breath sample before operation.

Will The Car Work If The IID Detects Alcohol?

If any degree of alcohol is detected, the vehicle will not start.

It also requires that you provide additional breath samples, typically in 5 to 15-minute intervals, and within 45-minutes after the engine started so as to preclude you from drinking while the car is in operation or the engine is still on.

How Much Time Do You Have To Provide A Breath Sample When Driving?

When the device requests a breath sample while you are driving, you have 6-minutes to pull over to a safe location and blow into the device.

Otherwise, the engine will shut down. While you have the IID, you have unlimited driving privileges.

Installation Requirements

If a judge or the DMV orders you to install an IID, you are required to:

  • Provide the DMV with a Department of Motor Vehicles Ordered Verification of Ignition Interlock (DL 924)
  • Pay a $45 administrative fee
  • Serve the specified suspension period
  • Provide California Insurance Proof Certificate (SR-22)
  • Pay any other installation fee
  • Have it professionally installed by a court-approved installer
  • Install an IID in every vehicle that you own (motorcycles are excepted)

Do I Need To Install The Ignition Interlock Device In A Work Vehicle?

Installation does not include any vehicle that is employer-owned or a vehicle that you drive for work purposes such as a van or truck.

How Long Does An Ignition Interlock Device Need To Installed?

Following a DMV suspension, most first-time offenders are given the option to have the device for 4-months.

In lieu of the device, the offender may select a restricted license for a period of 5 months that would permit driving to, from and during the course of employment and to and from the alcohol class.

Once the criminal case has concluded and there is a conviction in court on charges of VC 23152(a) or VC 23152(b), the period of time to have the device installed on a first offense is increased to 6 months.

How Long Is An IId Installed If There Was An Injury?

If an injury occurred with the DUI, the device requirement is 12-months following a conviction in court for VC 23153(a) or (b).

How Long Do I Need To Install The IID If This Is Not My First DUI?

For repeat offenders, the following time periods are required with an enhanced time if you are convicted of a DUI with injury under California Vehicle Code § 23153, or convicted of driving on a suspended license stemming from a DUI2:

  • 2nd DUI in 10-years: 1-year, but if an injury occurred: 2-years
  • 3rd DUI in 10-years: 2-years, but if an injury occurred: 3 years
  • 4th DUI in 10-years: 3-years, but if an injury occurred: 4-years

Do I Need To Install An Ignition Interlock If I Am Caught Driving On A Suspended License?

For driving on a suspended license, you risk having the device installed for 1-3 years.

These time periods apply to every driver convicted of a subsequent DUI or license suspension violation, regardless of the county where the offense occurred.

How Much Does An Ignition Interlock Device Cost?

It will cost you a minimum of $75 and up to $150 for a professional to install the IID. If you are low income, there is a program for financial assistance that can lower the cost by up to 50%.

There is also a recurring fee of about $50 for each time you bring the device in for calibration. These fees apply to each vehicle that you own.

The DMV has a fee of at least $55.

Counties That Require IID Installation

All California counties require installation of an IID for first-time DUI offenders. Following the changes in the law in cases with arrest dates on or after January 1, 2019, an IID is required upon conviction of all 23152(a) and 23152(b) charges.

  • Alameda
  • Los Angeles
  • Sacramento
  • Tulare

All first-time offenders in these counties are required to have the device for 4-6 months. If an injury occurred with the DUI, the device requirement is 12-months upon conviction of DUI with injury. For repeat offenders, the following time periods are required with an enhanced time if you are convicted of a DUI with injury3, or convicted of driving on a suspended license stemming from a DUI4.

How To Find A Court Approved Installer

You can find and have a court-approved installer by going to an DMV field office and getting a list, or by calling the DMV at 1-800-777-0133. There is also a web site: https://www.dmv.ca.gov/portal/dmv/detail/vehindustry/ol/forms/ignitioninterlockdevicelist

Ignition Interlock Frequently Asked Questions

Will an IID Damage my car?

No, the device is installed into the wiring of your car so no damage will be done to it. When the device is taken out, the wiring is restored to the condition it was in before installation. If you do not have it professionally installed, then you risk having your car damaged. Do not try to remove the device yourself.

Can An IID Device Be tricked?

It is highly unlikely that you can trick an IID. The device records a particular breath pattern that cannot be imitated. Some devices have a camera that records who is providing the sample or it may ask you to inhale to prove that you are a human providing the sample. And, if you do attempt to trick it, the device records each sample. It is a crime to do anything to circumvent the operation of the device.

Can an IID device have false positives?

Yes, on rare occasions the IID can produce a false positive. For instance, a spicy food could mix with HCI (hydrogen chloride gas) in your stomach to produce a methane gas, which is a hydrocarbon that the device is designed to detect.

Also, if you chew tobacco that contains ethyl alcohol, it will be detected. Mouthwashes and mouth sprays along with energy drinks can also register on the device as they contain ethyl alcohol as well. It is best to avoid these products well within the time before you decide to drive.

If I live in a county where the IID is not mandatory but I was convicted in Los Angeles County, will the judge require me to install an IID?

Yes. The county where you live is irrelevant. IIDs are required in all convictions of VC 23152.

If I am required to have an IID, do I get one immediately after ordered to do so?

 If you received an APS (Administrative Per Se) suspension rather than from the court and are a first offender, you may install the IID and apply for the restricted license and forego the suspension.

What if I do not own a car?

If you do not own a car, then request an exemption from IID installation using Exemption for Interlock Ignition Device (DL4055B) and submit to the DMV field office or mail it to Driver Licensing Mandatory Actions Unit within 30-days of your receipt of your suspension or revocation mail date.

What happens after the 4-6 month installation ends for a first-time offender? Do I get my regular license back?

If a first-time offender in any of the pilot counties, has the IID removed after the 4-6 month period by a certified installer. Your IID restriction is automatically removed but you will only receive a restricted license allowing you to driver to and from work or an approved DUI or alcohol treatment program until you complete the program.

Does the Ignition Interlock Device Shut Off A Car’s Engine?

No. The ignition interlock device will make the car’s horn sound if you fail a repeat breath alcohol test. The car’s lights will usually flash until you pass the breath test or until you shut off the engine.

What Happens If I Have An Ignition Interlock Device And Fail The Breath Alcohol Test?

If you have an ignition interlock device on your car and fail the breath alcohol test, the device will enter a short lockout period for several minutes. If you fail another breath alcohol test, the lockout period will be longer. The lockout period will allow alcohol to dissolve from your mouth and give you time to decide why you failed the test.

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Hiring An Attorney

The state of California has implemented tough drunk driving laws, including the requirement of having ignition interlock devices installed on cars of repeat DUI offenders. Drivers who have been convicted of Driving under the influence in California may have worries about possible license suspensions and may also have worries about being able to drive their children to school and drive themselves to work with an ignition interlock device on their car.

At the Aizman Law Firm, our experienced DUI attorneys can help you with questions you might have overlooked about going on with a normal life while an ignition interlock device is installed on your car. Contact us at 818-351-9555 for a free confidential consultation.

Legal References

  1. SB-1046 []
  2. California Vehicle Code § 14601 []
  3. CVC § 23153 []
  4. CVC § 14601 []


In 2016 got a Dui . 08,and2014 dui . 10 not sure offered deal for 2nd dui in 5 yr. Didn’t take it, attorney told me he could beat the . 08.lost and new law of 10 yr got me. So I end up with 3rd Dui from 2010.Right now I have 1 Dui in5 yrs or 2dui s in 10yrs.I personally had interlock put on my car. Love it. Pd fine off. Do I still have to do dui classes? I be done them over and over, jail time too. Only thing helpped me was interlock device. If I have to take dui classes, which one do I take? The One DUI class in 5yr period? Or the 2nd dui course or 3rd dui course. Are the dui classes sapost to go back 10 yr to? And I got the dui 2016,while in 52 week course. I thought getting a dui while in classes was added/included. I was nt told I had to start back over and pay for 52 more classes. Can I make a motion to Judge I keep interlock on car for 5 yr. And no Dui classes? They tricker me bad. The interlock cost me there’s no story’s to tell or hear. It flat out works and you can’t drive at all intoxicated. I was broke down made to stay sober and not drive because car will not start if you drink. This gave me the chance to stay clean from alcohol, and My mind and body healed. I needed that interlock to clear my mind. I wouldn’t be sober today if I didn’t put interlock on. I was forced my by own self to put device on my car. Prison didn’t work, sap didn’t , Sap is good though. I needed more interlock. Please help me w questions. I live in ky.

Hi Trish: I’m sorry to hear that you are struggling with your obligations. I strongly suggest you contact an attorney in KY as they are in the best position to advise you on how to best proceed in your case.

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