In Arizona, the most common reason why a car would have a breathalyzer is that the driver received a DUI conviction or an Arizona Motor Vehicle Division license action. A court may also require the device as part of sentencing, probation, or another case-specific order.
At Suzuki Law Offices, our Phoenix DUI defense lawyers help clients understand why an interlock was ordered, how long the requirement may last, and what steps can protect their driving privileges.
Our team includes former law enforcement investigators, and RJ Suzuki is a former Assistant United States Attorney and former federal prosecutor.
What Is a Breathalyzer in a Car?
A breathalyzer installed in a vehicle is usually a certified ignition interlock device, often called an IID or CIID. It connects to the ignition and tests the driver’s breath before allowing the vehicle to start.
An IID is different from a handheld breath-testing device used during a traffic stop. A roadside device is generally used to help an officer investigate suspected impairment. An interlock remains installed in the vehicle and records information over time.
The device may record:
- Startup test results.
- Rolling retest results.
- Missed or refused samples.
- Suspected tampering or circumvention.
- Inspection and calibration records.
Why Do People Have Breathalyzers in Their Cars?
There are three common reasons why a vehicle would have a breathalyzer:
A Legal or Licensing Requirement
Most drivers use an IID because a court or the Arizona MVD requires it after an alcohol-related DUI conviction, license suspension, license revocation, or restricted-license process. Arizona generally requires a certified device in every vehicle the restricted driver operates.
Suzuki Law Offices can review the court order, MVD notice, and driving record to identify which requirement applies and when the restriction began.
Voluntary Safety and Accountability
A person may choose to install an IID without a court or MVD order. Voluntary installation can help someone avoid driving after drinking when they do not trust their ability to judge impairment or want an added safeguard.
Continued Monitoring While Driving
An IID does more than test the driver before startup. It may require rolling retests during a drive cycle. These tests are designed to confirm that the same alcohol-free driver remains in control of the vehicle.
The provider transmits reportable data to MVD. The information may also be available to a court or probation department when authorized.
How Does a Car Breathalyzer Work?
The driver blows into the device before starting the engine. If the breath alcohol reading is below the programmed limit and the sample is accepted, the vehicle can start. If the reading reaches the lockout level, the engine will not start.
During a trip, the device may signal the driver to provide another sample. A rolling retest is not designed to shut off a moving engine. Instead, a missed, refused, or failed test may be recorded and reported.
Arizona requires proof of compliance and calibration at least once every 90 days. Drivers should follow the provider’s service schedule because missed inspections can lead to a suspension or additional interlock time.
Is a Car Breathalyzer the Same as an Ignition Interlock Device?
Yes. When someone asks why a car has a breathalyzer, they are usually referring to an ignition interlock device.
“Breathalyzer” is an informal term for equipment that measures alcohol through a breath sample. “Certified ignition interlock device” is the more precise term for the unit installed in an Arizona vehicle under a legal driving restriction.
Can You Drive Another Car With an Interlock Restriction?
Generally, no. An Arizona driver subject to an interlock restriction may operate only a vehicle equipped with a functioning certified IID. This rule can apply to personal vehicles, borrowed vehicles, rental cars, and work vehicles.
A substantial emergency may create a narrow exception under Arizona law. Drivers should not assume that an emergency, employment need, or shared-car arrangement permits them to use a vehicle without an IID.
Before driving another vehicle, ask our attorneys to review the restriction. Driving without the required device can result in a criminal charge, license consequences, and added interlock time.
What Happens if You Fail or Bypass the Device?
A failed test, missed rolling retest, calibration problem, or attempt to defeat the device may be reported to MVD. The result depends on the type of event and the driver’s history.
Common Ignition Interlock Violations
- Asking another person to provide the breath sample.
- Driving a vehicle without a certified IID.
- Disconnecting, altering, or interfering with the device.
- Missing required inspections or calibration appointments.
- Failing to complete required rolling retests.
Arizona law allows MVD to extend an interlock period by six months for several reported violations. A conviction for driving without the required IID can add up to one year, and some compliance failures can suspend driving privileges or restart the required period.
Suzuki Law Offices can examine the device records, service history, notices, and surrounding facts when a client disputes an alleged violation.
Does a Car Breathalyzer Mean the Driver Was Convicted of DUI?
Not always. Many IID requirements follow a DUI conviction, but a driver may receive a restricted interlock license during an administrative suspension or after a refusal-related license action before the criminal case ends.
Voluntary installation also does not establish that the driver has been arrested or convicted. The reason for the device must be determined from the court order, MVD record, or the driver’s own decision.
Can a DUI Defense Lawyer Help With an Ignition Interlock Requirement?
Yes. A DUI defense lawyer can determine whether the requirement came from the court, MVD, or both. The lawyer can also review installation deadlines, restricted-license eligibility, alleged violations, and the date the device may lawfully be removed.
At Suzuki Law Offices, we explain the requirements in direct terms and help clients respond before a missed deadline or disputed report causes further license restrictions. Our team is available 24/7, including weekends, and we place a strong emphasis on prompt communication.
Speak With an Arizona DUI Lawyer About a Car Breathalyzer
Understanding why someone would have a breathalyzer in their car can help you avoid a violation and protect your ability to drive. Arizona’s interlock rules can affect which vehicles you may use, how often the device must be serviced, and how long the restriction remains in place.
Contact Suzuki Law Offices for a free consultation. We will review your court and MVD documents, explain your options, and help you respond to an ignition interlock requirement or reported violation.
Call or text (602) 682-5270 or complete a Free Case Evaluation form