What Really Happens If I Fail My Ignition Interlock Breath Test?
If you are going to have an ignition interlock device (IID) installed in your car, you might be worried about what can happen if you fail the breath test, i.e. if you blow an alcohol reading above the designated level.
What does happen after a fail depends on a couple of things — mainly, why you fail and when you fail. The important thing is not to panic. If you have not been drinking, you will be able to get back on the road and get on with your day.
Why you fail. You can fail an IID breath test for one of several reasons. It might be that you used an alcohol-based mouthwash, or fermentation has turned a bit of fruit juice in your mouth to alcohol. Even the fermentation of yeast in bread or pizza dough could supply an alcohol molecule or two, could be enough to cause a fail. It might also be that you were drinking the night before, and there is some residual alcohol in your system.
When you fail. There are two different times you will take a test on an ignition interlock:
- the initial test, performed when you start the car, and
- the rolling re-test, which is done a few minutes after you begin driving and periodically thereafter
If you fail the initial test, your vehicle won’t start. You must wait a designated time — called the lockout period — before testing again. The lockout periods vary by state. In Washington State, for example, if you fail your initial test you can blow again in 5 minutes. If you fail that one, you must wait 15 minutes. After that, the lockout periods are 45 minutes and 24 hours.
If you failed your initial test because of something you ate, just wash out your mouth and re-test. If you were drinking the night before, you need to wait until all the alcohol has dissipated from your system. It’s hard to calculate how long this takes, which is why it is recommended that you not drink any alcohol while an interlock is installed on your vehicle. Of course, if you were drinking prior to your initial test, you should not drive. Wait until you are fully sober.
The procedure is different if you fail a rolling re-test. If you blow a fail while driving, you must pull over as soon as possible and shut off the ignition. After 5 minutes, you will be asked to perform an initial test and start the car again.
Note: failing a rolling re-test puts your ignition interlock into Early Service Recall mode. You must take your vehicle to your service center to have it reset and have data downloaded.
A failed test on an ignition interlock is not the end of the world. Just remember to keep calm and follow the above procedures, and you’ll be back on the road in no time.