New York DMV Permit Written TestAlcohol and Drug LawsMedium

A driver is required to install an Ignition Interlock Device (IID) in their vehicle as part of a DWI conviction. They attempt to start the car, but the device prevents it from starting. What is the most likely reason for this?

  1. AThe device requires a warm-up period after being turned on.
  2. BThe device detected alcohol on the driver's breath.
  3. CThe driver forgot to enter a required security code.
  4. DThe driver did not blow hard enough into the device.
Show answer & explanation

Correct answer: B. The device detected alcohol on the driver's breath.

The primary function of an Ignition Interlock Device (IID) is to prevent a vehicle from starting if it detects alcohol on the driver's breath, typically above a very low, pre-set BAC limit. This is its core safety mechanism.

Why the other options are wrong

  • A. Some devices have a brief warm-up, but this typically results in a 'please wait' message, not a lockout due to a failed test.
  • C. Not all IIDs require a security code, and a failed code entry would be a different type of lockout indication.
  • D. While insufficient breath can cause a failed test, the direct prevention of starting is usually due to alcohol detection.

Ignition Interlock Device (IID) Function

An Ignition Interlock Device (IID) is a breath alcohol analyzer installed in a vehicle that prevents the engine from starting if the driver's breath alcohol content exceeds a pre-set limit.

  • Prevents vehicle from starting if alcohol is detected.
  • Requires periodic 'rolling retests' while driving.
  • Records all activity (pass, fail, tamper).
  • Mandatory for certain alcohol-related driving convictions.

Memory trick: Blow clean, or the car is keen to stay still.

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