Ignition interlock devices (commonly referred to as IIDs) are miniature DUI breath test instruments that are installed in the dashboard of your car and prevent your car from operating unless you provide an alcohol-free breath sample. IIDs are increasingly popular as a California DUI penalty.
In this article, our California DUI defense attorneys answer the following frequently asked questions about ignition interlock devices and California DUI law:
- 1. What is an Ignition Interlock Device, and How Do IIDs Work?
- 2. Will I Have to Install an IID If I Am Convicted of California DUI?
- 3. How Much Does a California Ignition Interlock Device Cost?
- 4. How Do I Find a Court-Approved IID Installer?
- 5. Can a California IID Register a "False Positive"?
If after reading this article, you have additional questions, we invite you to contact us at Shouse Law Group.
As previously stated, an ignition interlock device is a type of mini-breathalyzer instrument. About the size of a cell phone, it is installed on the steering column of your car.
If the judge orders you to install an IID as part of your California DUI probation, you must:
- have the IID professionally installed, and
- have an IID installed in every car you own or drive.1 (Employer-owned cars2 and motorcycles3 are exempt from this rule.)
Before you start your car, you must blow into the IID and provide an alcohol-free breath sample. If you don't, your car will not start. Once you are driving, the IID will ask for random samples, between 5-15 minutes after you begin driving and then about every 45 minutes thereafter.
When the instrument asks for these "rolling" samples, you have six minutes to provide a sample--plenty of time to pull over if you don't feel that you can safely provide a sample while driving.
If you don't "pass", your ignition interlock device will not disable your car. The IID will, however, register a "fail" on your log that gets reported to the court.
It must be noted that California ignition interlock devices are designed to ensure that only you as the driver can provide your own breath sample. This is accomplished by:
- requiring a specific breath pattern for the sample,
- having a very short cord that will not reach to the passenger or back seats,
- requiring random samples, even while driving, and
- making it a crime to ask someone else to fraudulently provide his/her sample in lieu of yours.4
In addition, the technology of California IIDs is so advanced that the IID detects and records:
- any attempts to disconnect or tamper with the device,5
- all engine starts and stops, and
- all breath test results.
Once you have installed a California IID, you must take it in for servicing at least every 60 days.6
A judge may order you to install a California ignition interlock device (IID) for:
- a first offense of violating Vehicle Code 23152(a) VC driving under the influence, especially if the defendant's BAC of .015% or higher,
- a first offense of refusing to submit to a chemical blood or breath test,
- a first offense of violating Vehicle Code 23152(b) VC driving with a blood alcohol concentration (BAC) of 0.08% or greater, or
- Vehicle Code 14601 VC suspended license violations stemming from DUI convictions.
Meanwhile, a judge will order you to install an IID for
- repeat DUI convictions, or
- Vehicle Code 23153 VC DUI causing injury.7
In addition to situations where a judge may require you to install an ignition interlock device, there are a number of DUI conviction scenarios where a judge must require you to install an IID.
First-time DUI offenses
The length of time that a first-time DUI defendant may be required to keep an IID in their car following conviction is usually 6 months.8 (If the defendant does not get convicted of DUI but is found liable by the DMV, the mandatory period for having an IID is usually 4 months).9
Repeat DUI offenses
Under California law, a criminal judge must order you to install a California IID for a period of:
- one (1) year following a second DUI conviction,
- two (2) years following a third DUI conviction and
- three (3) years following a fourth or subsequent conviction.10
And if you are convicted of a second DUI causing injury, you must install the IID for two (2) years (three years for a third conviction).
(If the defendant does not get convicted of DUI but but is found liable by the DMV, the mandatory period for having an IID is usually just one year, no matter whether it's a second or third conviction.)
The following table summarizes the required period of IID installation:
Type of DUI Conviction
Period of Mandatory IID Installation (if the driver wants to continue driving during the license suspension period)
VC 23152(a) or 23152(b): first offense
VC 23152(a) or 23152(b): second offense
VC 23152(a) or 23152(b): third offense
VC 23152(a) or 23152(b): fourth or subsequent offense
VC 23153 DUI causing injury: first offense
VC 23153 DUI causing injury: second offense
VC 23153 DUI causing injury: third offense
Mandatory IID for VC 14601 driving on a suspended license
There are requirements for IID installation following one or more convictions for Vehicle Code 14601 driving on a suspended license when the suspension / revocation was based on a DUI conviction.
Depending on the exact license violation--and on how many prior DUI and/or suspended license violations you have suffered--the judge may order you to install an IID for one (1) to three (3) years.11
IID as a condition of a restricted license
If you are a repeat DUI offender and wish to obtain a restricted driver's license, the California DMV will require you to install an IID as well.12 A restricted license allows you to drive to/from work, school, or a court-ordered alcohol program while your driver's license is otherwise suspended or revoked. Note that starting in 2019, judges are usually willing to let DUI defendant drive anywhere as long as they have an IID installed in the car for a predetermined period of time.
On average, the cost of a California IID is about $2.50 per day. Some companies additionally charge around $75-$100 for installation. You may also be required to pay fees for maintenance and calibration of your ignition interlock device.
Under California's mandatory IID pilot program law (Vehicle Code 23700 VC), if you can't afford the cost of your mandatory IID, you will only be required to pay a portion of the costs.13
If a California court requires you to install an ignition interlock device on your car, you must go to an authorized installer to have it done. Several private companies are approved by the courts.
IID installation companies you may want to consider include:
- Smart Start of California,
- Guardian Interlock,
- Sens-O-Lock, and
- Alcohol Detection Systems.
Most ignition interlock devices operate on fuel cell technology. Fuel cell technology is alcohol-specific and isn't affected by outside interference. This means that there is little chance of your IID registering a "false positive" because of cigarette smoke, perfume, gasoline, etc.
However, any amount of alcohol that is blown into an ignition interlock device will register. This means that if you use mouthwash with alcohol in it, eat liquor-filled candy, or even eat a pastry (sometimes the combination of sugar and active yeast produce low levels of alcohol), the IID will pick up on and register alcohol in your blood sample.
The good news is that when alcohol registers, you will usually be given the opportunity to retest almost immediately. The low levels of alcohol that may be present in these types of situations quickly disappear. Rinsing your mouth with water in between samples can help to expedite this process.
Call us for help . . .
If you or a loved one has been arrested for DUI and would like to learn more about ignition interlock devices (IIDs), we invite you to contact us at Shouse Law Group.
We have local offices in Los Angeles, the San Fernando Valley, Pasadena, Long Beach, Orange County, Ventura, San Bernardino, Rancho Cucamonga, Riverside, San Diego, Sacramento, Oakland, San Francisco, San Jose and throughout California.
For information about Nevada ignition interlock devices, go to our article on Nevada ignition interlock devices.
- California Vehicle Code 23575 VC -- Court-mandated use of ignition interlock device. ("(a)(1) In addition to any other provisions of law, the court may require that a person convicted of a first offense [DUI] violation of [Vehicle Code] Section 23152 or 23153 install a certified ignition interlock device on any vehicle that the person owns or operates and prohibit that person from operating a motor vehicle unless that vehicle is equipped with a functioning, certified ignition interlock device. . . . (l) This section does not restrict a court from requiring installation of an ignition interlock device and prohibiting operation of a motor vehicle unless that vehicle is equipped with a functioning, certified [California] ignition interlock device for a person to whom subdivision (a) or (b) does not apply [who has previously been convicted of Vehicle Code 23152a driving under the influence].")
- California Vehicle Code 23576 VC -- Motor vehicle owned by employer; exception. ("(a) Notwithstanding [Vehicle Code] Section 23575, if a person is required to operate a motor vehicle in the course and scope of his or her employment and if the vehicle is owned by the employer, the person may operate that vehicle without installation of an approved ignition interlock device if the employer has been notified by the person that the person's driving privilege has been restricted pursuant to Section 23575 [requiring mandatory use of a California IID] and if the person has proof of that notification in his or her possession, or if the notice, or a facsimile copy thereof, is with the vehicle. (b) A motor vehicle owned by a business entity that is all or partly owned or controlled by a person otherwise subject to Section 23575, is not a motor vehicle owned by the employer subject to the exemption in subdivision (a).")
- California Vehicle Code 23575 VC -- Court-mandated use of ignition interlock device -- subdivision "m". ("(m) For the purposes of this section, "vehicle" does not include a motorcycle until the state certifies an ignition interlock device that can be installed on a motorcycle. Any person subject to an ignition interlock device restriction shall not operate a motorcycle for the duration of the ignition interlock device restriction period.")
- California Vehicle Code 23247 VC -- Violation of Vehicle Code 13352 or 23575 VC; punishment; defenses. ("(b) It is unlawful for any person whose driving privilege is restricted pursuant to Section 13352 [because of a California DUI conviction] or 23575 [requiring the mandatory installation of a California IID] to request or solicit any other person to blow into an ignition interlock device or to start a motor vehicle equipped with the device for the purpose of providing the person so restricted with an operable motor vehicle. (c) It is unlawful to blow into an ignition interlock device or to start a motor vehicle equipped with the device for the purpose of providing an operable motor vehicle to a person whose driving privilege is restricted pursuant to Section 13352 or 23575.")
- See same. ("(g)...The installer shall notify the Department of Motor Vehicles if the device is removed or indicates that the person has attempted to remove, bypass, or tamper with the device, or if the person fails three or more times to comply with any requirement for the maintenance or calibration of the [California] ignition interlock device.")
- See same. ("(g) A person whose driving privilege is restricted by the Department of Motor Vehicles pursuant to Section 13352 [a restriction based on a California DUI] shall arrange for each vehicle with an ignition interlock device to be serviced by the installer at least once every 60 days in order for the installer to recalibrate the device and monitor the operation of the device.")
- California Vehicle Code 23575 VC -- Court-mandated use of ignition interlock device. ("The court shall give heightened consideration to applying this sanction to a first offense [DUI] violator with 0.15 percent or more, by weight, of alcohol in his or her blood at arrest, or with two or more prior moving traffic violations, or to persons who refused [to submit to] the chemical [blood or breath] tests at arrest.")
- California Senate Bill 1046 (2018).
- See same.
- California Vehicle Code 23573 VC -- Violations necessitating ignition interlock device... ("(j) In addition to all other requirements of this code, a person convicted of any of the following violations shall be punished as follows: (1) Upon a conviction of a violation of Section California Vehicle Code 14601.2, 14601.4, or 14601.5 [DUI-related license suspensions] subsequent to one prior conviction of a violation of Section 23103.5, 23152, or 23153, [a California wet reckless or DUI] within a 10-year period, the person shall immediately install a certified ignition interlock device, pursuant to this section, in all vehicles owned or operated by that person for a term of one year. (2) Upon a conviction of a violation of [Vehicle Code] Section 14601.2, 14601.4, or 14601.5 subsequent to two prior convictions of a violation of Section 23103.5, 23152, or 23153, within a 10-year period, or one prior conviction of Section 14601.2, 14601.4, or 14601.5, within a 10-year period, the person shall immediately install a certified ignition interlock device, pursuant to this section, in all vehicles owned or operated by that person for a term of two years. (3) Upon a conviction of a violation of [Vehicle Code] Section 14601.2, 14601.4, or 14601.5 subsequent to three or more prior convictions of a violation of Section 23103.5, 23152, or 23153, within a 10-year period, or two or more prior convictions of Section 14601.2, 14601.4, or 14601.5, within a 10-year period, the person shall immediately install a certified [California] ignition interlock device, pursuant to this section, in all vehicles owned or operated by that person for a term of three years.")
California DMV website - ("If you have been convicted of a second or subsequent DUI violation and have completed at least one year of your DUI suspension/revocation you may qualify for a restricted driver license if you meet these requirements:
- Install an IID on your vehicle and provide DMV with a "Verification of Installation" Ignition Interlock (DL 920) form.
- Clear all other outstanding suspensions/revocations on your driving record.
- Comply with a DUI program's requirements and have the program provider submit either a Proof of Enrollment Certificate (DL 107) or Notice of Completion Certificate (DL 101) form to DMV (whichever applies to your case).
- Submit an Insurance Proof Certificate (SR 22) form issued by your auto insurance company to DMV establishing proof of financial responsibility.
- Pay all required fees, including the $15 IID restriction fee.")
- See California Vehicle Code 23700 VC -- Pilot program to reduce driving under the influence offenses [through mandatory IID installation for first offenders]; establishment in Alameda, Los Angeles, Sacramento, and Tulare Counties, endnote 8 above.