The BDI-747 Ignition Interlock Device

The BDI-747 Ignition Interlock Installed within your vehicle is an electronic breath alcohol analyzer.
The BDI-747 Ignition Interlock is connected with the ignition and other control systems of your motor vehicle.
The BDI-747 Ignition Interlock measures the BAC (Blood Alcohol Content) of the driver of your vehicle, and prevents the vehicle from being started if the driver’s BAC exceeds the preset limit determined by the state’s specifications.
The BDI-747 Ignition Interlock is comprised of a detachable Sample Head and a Data Logger Module.

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Reading the Lights on your BDI-747

Power to Handset is On

  • Left Light = Red
  • Right Light = Red & Blue

* Holding the middle button down for approximately five seconds (until the right light turns blue and stays on) will turn the device on.

Power to Handset is Off

  • Left Light = Red
  • Right Light = Off

* Holding the middle button down for approximately five seconds (until the right light turns blue and stays on) will turn the device on.

Handset Locked (Must Reboot)

  • Left Light = Red
  • Right Light = Solid Blue

* To reboot the handset at any time hold down all three buttons for approximately five seconds until the screen flashes or turns off. Next, release the buttons to activate the device will reboot sequence.

To Enter Password Mode

* Power to handset must be on & the screen must be blank. While holding down the right button, turn the ignition key to the “ON” (accessory) position. Tap the password box, once a number pad appears, enter the correct code, then close the number pad and press enter.

Starting Your Vehicle:

Standard Test

  • Turn the ignition key to the “ON” (accessory) position. (DO NOT TURN THE KEY TO THE START POSITION AT THIS TIME.) Make sure your mouthpiece is inserted into the handset.
  • Hold down the middle button until the right light turns blue.
  • Make sure the device reads “LINK ON”, if it does not turn the ignition key back to the “OFF” position then back to the “ON” position.
  • The display will indicate the next service date.
  • Wait until the display indicates “Test required, Please Provide Breath Sample”.
  • Take a deep breath and blow steadily until the unit produces an audible click.
  • The display will then read “Measuring Sample” and show a progress bar.

Test Results:

If the test was successful, the display will read “Test Passed”. You now have 2 minutes to start the vehicle.
If the test was unsuccessful, the display may read “Blow test error, Please try again”. This message indicates the person providing the sample was not blowing into the device hard enough or long enough to complete the test. You may immediately attempt another breath test.
The display may also read “Test failed”. Wait for the system to reset and try again. Depending on the regulations in your state you will be given a specific number of opportunities to pass the test. If you are unable to pass the test with the allotted number of attempts, the unit will lockout for a preset amount of time. Once the lockout is over you will be given another series of attempts to pass the test.

Rolling Retests:

After the vehicle has been running for a predetermined period, the device will beep and the display will read “Please blow rolling test”. The display will also show a countdown indicating the amount of time available to complete the rolling test. You must successfully deliver a breath sample in order to complete the test. The breath sample process is the same as the initial test.

The display will again show “Measuring Sample” and a progress bar. You will also receive one of the test result prompts described in the Test Result section of this guide.

Additional rolling retests will occur randomly during the operation of the vehicle depending on your state’s requirements.

If you miss or fail a rolling retest the unit WILL NOT stop your vehicle, however, your vehicle’s horn will sound, the headlights will flash and an audible tone will be emitted from the unit until the vehicle is stopped. A new breath test will be required to restart the vehicle. If your state’s requirements do not allow for the use of the vehicle’s horn or headlights then they will not be activated.

Please Note

Service Requirements:

The system indicates the next service appointment every time it prepares for a test.
* You are required by the state to have your device serviced at regular intervals.
Your next appointment, as scheduled on your paperwork, should be the same as the date in the display. Should the system reset the service days, the date displayed on the unit will change to indicate the day the unit will lock out. * If the unit enters the stop service mode, you will need to contact EZ Interlock LLC. for assistance.

Violations and Early Service Recalls:

Certain events will cause the interlock device to automatically enter an early service recall state. The interlock device must be reset within a certain number of days to prevent it from entering a stop service mode. IF THE INTERLOCK DEVICE ENTERS STOP SERVICE MODE YOU WILL NOT BE ABLE TO USE THE DEVICE OR START YOUR VEHICLE.

If the event of an early service recall OR stop service mode, you must call EZ Interlock, Inc. at 480.809.6202 to report the early service and to schedule an appointment to have the interlock device reset. You may also be provided with a code that can be entered into your interlock that will reset the device. The following circumstances may cause an early service:

  • Attempting to start your vehicle prior to taking a breath test or tampering with the device will cause a start violation. You will have 5 days to have the device serviced before it enters the Stop Service mode.
  • Failing or refusing a rolling retest will result in a retest violation. You will have to have the device serviced before it enters the Stop Service mode.
  • Repeatedly disconnecting the vehicle’s battery or having maintenance work done to the vehicle can also cause the unit to enter the early service mode. If this happens, you will have to have the device serviced before it enters the Stop Service mode.
  • If you have too many fails within the monitoring period a BrAC violation will occur. You will have to have the device serviced before it enters the Stop Service mode.

Helpful Tips:

  • It is highly recommended that you remove the handset when shutting off and exiting the vehicle in order to shorten the warm up time and protect against theft.
  • Also, when turning off the vehicle, the unit will display a countdown. This indicates the amount of time you have before the unit powers down. The vehicle can be restarted at any time during this countdown. Wait until the unit powers down before disconnecting the handset.
  • Hold the middle button on the head to power down the device.
  • Retain all receipts for parts or service performed on your vehicle. It is highly recommended you be present for repairs to your vehicle. You will need to provide your interlock service center with these receipts if a bypass is recorded on your device.
  • You can safely replace your vehicle’s battery and change your oil with an interlock system installed. NOTE: It is recommended that you disconnect your sample head before attempting to service your vehicle’s battery.
  • Wait at least 15 minutes after using a product that contains alcohol or after eating before attempting a breath test. Products such as mouthwash, cough syrup, and breath sprays may contain alcohol. Eating certain foods may result in a positive alcohol reading.
  • WARNING: Before taking a test make sure all food and other substances are completely out of your mouth. Clear your lungs several times. If needed, drink water before a test to assure that no foreign substances are present. Introducing liquids, food particles, or tobacco smoke can affect the unit’s operation.

BDI-747 Components


Only mouthpieces obtained from EZ Interlock, Inc. may be used in your interlock device’s sample head.

Sample Head:

The sample head is the portion of the interlock device that accepts your breath sample. An LCD screen on the face of the head provides user information such as service dates, error messages, test results, and test instructions. Three buttons located beneath the screen allow the user to enter service codes. These buttons are not normally used during operation of the device. Please contact EZ Interlock prior to entering a code. The sample head should be taken out of the vehicle when it is not in use.

Coiled Cord:

The coiled cord is the cable that connects the head to the data logger. The ring connectors on the head and coiled cord can be detached by pulling down on silver ring nut and gently pulling the cable out of the head unit so that the head can be used wirelessly or taken out of the vehicle. Make sure the coiled cord is placed in a secure location when the head is not connected in order to avoid damage. It is also a good idea to check the connectors on the head and coiled cord for dirt and debris regularly as either could prevent the device from functioning properly.

Data Logger:

The data logger is the portion of the unit that contains the starter, horn, and headlight relays. It also contains secondary data storage. This prevents complete data loss in the event of a sample head malfunction. This portion of the device is located under the dash of your vehicle and is not accessible to the user.

Defective Equipment:

If it becomes necessary to repair or replace defective equipment, please contact EZ Interlock, Inc. to schedule a service appointment at your earliest convenience.

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