Q: I’ve seen information on TV about how insurance companies can supposedly track how a car is driven. How much information is available about my car and personal choices to someone who is capable of snooping?

A: This is a large concern for many people. I’m familiar with what is possible to obtain from a vehicle’s data link connector but don’t have the resources to be sure of the extent to which it may be collected and used, beyond the examples below.

The onboard diagnostics data link connector beneath the instrument panel of vehicles made in 1996 and on, an OBD-II, can provide two types of information: federally mandated generic diagnostic information and manufacturer-specific, all-vehicle information. Easily acquired data include a couple of dozen powertrain parameters such as vehicle speed/rate of change, engine rpm, throttle position/rate of change and brake switch status. Recording and transmitting this data with a plug-in device can provide a general indication of how a vehicle was/is being driven. Esurance’s voluntarily installed DriveSense is one example, allowing a possible rate discount for gentle driving behavior. Not seen/available are yaw (turning), vehicle location/route, following distance, seat belt usage, seat position/occupancy, entertainment and communication choices, and other rather intrusive data. These fall under the manufacturer-specific and/or supplemental restraint system (airbag) event data categories.

All OBD-II vehicles can record a freeze frame (snapshot) of the data occurring at the instant of an emissions failure that results in an illuminated check engine light. This is useful to a technician as it allows the best chance to duplicate the fault so it can be diagnosed and the repair validated. Some vehicles go further by recording a more comprehensive before/during/after movie of conditions which can include engine/emissions-related, manufacturer-specific data.

Recent vehicles also record and store crash data, which provides a vivid picture, via dozens of sensors, of what was happening prior to an airbag deployment, and some less-severe incidents. This information can help make future cars safer and perhaps mitigate lawsuit damages. A 2014 Chevy Silverado, for example, can record and playback well over 100 printed pages of crash data after an incident.

As long as you don’t crash or voluntarily attach a telematics device to your vehicle, your privacy seems safe for now. Manufacturer-specific information could provide the more intrusive information listed above, but since this data are less-standardized in format, we’re hopefully a while away from big brother and big business accessing our Bluetooth activity, cabin conversations and radio station choices.

— Bergholdt teaches automotive technology. Email questions to under-the-hood@earthlink.net.