The biggest interlock program failures aren’t caused by drinking. Most failures are caused by missing calibration windows, poor sample collection, electrical failures and lack of proper documentation. I advise people who are restricted from driving during certain times of the year, and I try to set them up so that they can complete a year of interlock monitoring instead of having to extend their monitoring for a year or more. There are a few simple practices that need to be put into place in the first two weeks of monitoring to set a person up properly to complete a year of interlock monitoring.
Getting the installation right the first time
The quality of the interlock installation is important. The handheld unit that has been spliced into an unstable ignition circuit can intermittently suffer from power loss. These events will be logged within the interlock monitoring device and at some point in the future they will be reviewed by someone. Therefore, it is very important that the interlock monitoring device is tested by the installer prior to the installation of the monitoring device, and in particular the battery and the vehicle’s charging system are tested. A battery that is near the end of its life will drop voltage under certain operating conditions and this could be mistaken for a person attempting to tamper with the interlock monitoring device.
Vehicle factors that complicate the job
As a note of particular importance for Ignition Interlock Installers, hybrids and vehicles with push-button start systems as well as those that have been fitted with aftermarket alarms and/or remote starters will require special wiring approaches for the interlock. In addition, clients of such vehicles will want to be advised that remote start functions on such vehicles will be disabled and/or reconfigured so as to require a passing sample to start the vehicle’s engine.
- Confirm the shop has installed on that make and model before, particularly for European vehicles with sensitive CAN bus systems
- Ask whether the camera unit placement will obstruct the driver’s view, since a badly mounted camera invites both citations and blocked images
- Verify the handset cable has enough slack to reach the driver’s mouth comfortably without stretching across the steering column
- Get the serial number and installation certificate copied before leaving the shop
Daily technique that prevents false positives
There are many other substances which can also cause failed samples. Examples include mouthwashes, breath sprays, cough medicines, protein powders and other fermented foods. However, it is relatively easy to eliminate the effects of most of these by simply rinsing your mouth with water and waiting 15 minutes before providing a sample.
Sample technique is critical when it comes to passing interlock tests. For example, a complete interlock test (a ‘pass’) consists of the test taker making a steady stream of air through a mouthpiece for a few seconds. There is then a ‘hum’ or a ‘suck-back’ of air into the mouthpiece. If the test taker is producing inconsistent pressure (up and down) while blowing into the mouthpiece of an interlock test unit, then the test taker will get an ‘incomplete sample’ reading and therefore fail the test.
Handling rolling retests safely
Interlock devices usually allow several minutes to complete a retest. A retest does not necessarily require a driver to pull over and get in danger. A driver may pull into a safe location, such as a parking lot, to complete a retest. Interlock devices are programmed to prompt and horn until a complete sample is taken for a retest.
Servicing intervals and what happens at each visit
Once the last service has been completed, the interlock system will lock up after a predetermined time. This time frame is pre-programmed at the time of manufacturing and cannot be changed by the interlock service provider. The lock up of the interlock system will require a tow to a service provider to have the lock up cleared. The cost for this can range from $200 to $500 or more.
| Stage | Typical timing | What occurs |
| Installation | Day one | Wiring, calibration, driver training, initial report filed |
| Routine service | Every 30 to 60 days | Sensor calibration, data download, firmware check, violation review |
| Early lockout warning | 5 to 7 days before deadline | Countdown displays at each start; vehicle still operates |
| Permanent lockout | After deadline | Vehicle will not start; service visit or unlock code required |
| Removal | End of requirement | De-installation, final data report, wiring restored |
Reading the data log before the monitoring authority does
Request a copy of the service report for every service visit. In the event of a warm restart or low-voltage event (even if it was not the cause of the failed test), having a written explanation of what happened is so much better than receiving a verbal explanation of events after a notice has been issued. The fact that a provider hands over reports when asked is a good indicator of a quality provider.
Choosing a provider that will not create problems
A provider’s certification to install and monitor interlock devices by the state’s relevant agency does not necessarily mean that provider is better than another. Most important is the size of the provider’s service network, the number of and time of day of appointments available and whether the provider’s own people come to the driver’s car and do the work or whether the work is subcontracted out to a variety of independent repair shops.
- How many service locations are within reasonable driving distance, and what are the after-hours options
- Is a 24-hour support line staffed by people who can issue an emergency unlock code
- Are calibration fees, lease costs, and violation reset charges disclosed as a single monthly figure
- What is the turnaround time for a replacement handset if a unit fails
Regional coverage for traveling drivers is very important. Drivers in the valley are usually best served by Sacramento ignition interlock services that operate several shops across the metro area, so that a simple calibration does not end up consuming a driver’s entire day.
Documentation habits worth keeping
Remember that for the length of time required (which will vary by State and by individual case), and for a reasonable time thereafter, you will need to retain copies of all service receipts, of all calibration certificates, and of all installation records. The driver will be held accountable for any errors in the filing of these reports. It is therefore wise to retain all service records, in a single file, and to check with the Monitoring Authority, and/or with qualified counsel, to find out what the requirements are for the client’s individual circumstances. In the meantime, the service provider will have filed the reports required.
