In the past, it was only performance and racing enthusiasts who took the time and effort to install telemetry systems into their vehicles so they would be able to track the data being produced by the car for analysis. This data includes all of the measurements that have to share the dashboard gauges, but with full accuracy values rather than just a speedometer needle-style gauge.

on board diagnostics fig

In racing, this real-time information is critical to understanding the full status of the car to get the maximum performance. Some of the telemetry systems even allowed two-way communication to be able to adjust parameters, or give feedback to the driver when he adjusts the parameters in the vehicle.

This need for engine and operation data has increased in sophistication, as the level of engine control electronics has increased. Current cars cannot get by with the “idiot light” system of the pre-1990s vehicles. As a result, the OBD (On-Board Diagnostics) system was put into cars to generate error codes for their status.

The current version, OBD2, was standardized in the US in 1996 with a common 16-pin connector that has to be located within the cabin area not more than two feet from the steering wheel (see standard placement near the glovebox). This makes the vehicle data available for everything from exotic sports cars to minivans to the new EVs that are on the market.

The in-cabin access of this connector allows for many new applications besides engine diagnostics at the time of maintenance. For example, companies like Progressive Insurance have created a client plugin product called “Snapshot.” The unit connects to the OBD2 port of the car and sends VIN, time and distance information to the Progressive cloud servers. This data is then analyzed for driving habits and is used as part of the criteria for determining insurance rates. This technology is now also available in a generic form for most smartphone users on Android.

There are multiple companies that sell a Bluetooth-enabled plug that ranges from $10 to $30 that can connect to different vehicles. Although the plug is standardized, the firmware to connect and read codes from different ECUs (Engine Control Units) still requires multiple products. If you purchase a unit, make sure it lists the make and model of your car, so you get the right one.
Most units will support cars from multiple auto manufacturers. These modules allow for wireless, real-time data collection and analysis on a mobile device using apps that range from free to sub $10. For the home enthusiast, this replaces the traditional OBD2-to-USB cable that allows for connection to professional garage diagnostic systems.

Several screenshots of the industry-leading Torque Pro app for android (the paid version of the Torque Lite free app) show typical displays. There are real-time gauges, diagnostic codes and explanations, trip monitoring, interface to GPS, and many other functions. All the data is collected and available for download for post-trip analysis. The system also supports plug-ins that integrate a number of these gauges as an overlay to video on the device or for a heads-up display in the vehicle.

This technology will allow manufacturers to be able to track and better support the vehicles by understanding what the car was doing prior to a problem – as is being done by Tesla Motors and GM. It will also allow regular folks to care about using their car properly, and to get the best performance, economy and care of the vehicle on a real-time basis without the expense of intermediate visits to the dealer to “check what it is doing.”

Digest: On-board diagnostics not just for racing anymore by Pallab Chatterjee