Ignition Interlock Devices in Texas: What You Must Know
Ignition Interlock Devices in Texas: What You Must Know to Stay Out of Trouble
If a judge orders interlock, you must understand the rules to avoid violations and new charges.
What Is an Ignition Interlock Device?
An ignition interlock device (IID) is a breath alcohol-testing system installed in your vehicle that prevents the engine from starting if alcohol is detected. Courts use interlock devices to monitor drivers accused or convicted of alcohol-related offenses, especially DWI.
When Is Interlock Required in Texas?
Under Texas Code of Criminal Procedure Art. 17.441, judges must require interlock as a condition of bond if the case alleges:
- Second DWI or more, or
- First DWI with a BAC of .15 or higher
Judges also have discretion to order interlock based on case circumstances — such as prior alcohol-related history.
How Interlock Violations Occur
Many people assume compliance is easy. But common technical issues become violations:
- Missed rolling retests (you must blow again while driving)
- False positives from mouthwash or acetone
- Power loss from battery disconnects
- Using someone else’s vehicle
Every action is logged. Courts and supervision officers review the data.
Can You Drive Without Interlock Installed?
No — not even once. If your bond or probation requires interlock, driving a vehicle without it is a new criminal offense and can lead to jail and revocation of bond.
Cost and Vendors
The court will typically provide a list of approved vendors. Costs vary, but drivers should expect:
- Installation: $70–$120
- Monthly fees: $60–$100
- Removal fee: $50–$100
If needed, we can request financial hardship adjustments.
When Can Interlock Be Removed?
Removal depends on the resolution of your case:
- Case dismissal or acquittal = removal request filed immediately
- Probation cases = specific compliance period must be completed
- Deferred cases = requirements vary by court orders
Your attorney should file paperwork — never have a vendor remove it without judicial approval.
How We Defend You Against Interlock Problems
If a violation report is filed, we focus on:
- Device inaccuracies
- Medical conditions (e.g., diabetes)
- Unauthorized data transmission
- Maintenance or power-related issues
Judges respond very differently when presented with clear technical documentation instead of excuses.
Don’t Let a Device Ruin Your Case
If you have interlock requirements or a violation issue — take action quickly.
Call now for guidance: (936) 777-4891