Vehicles manufactured since 1996 have had to comply with the CARB issued OBD-II specification. These vehicles use a standardized diagnostic connector and data output format. On-Board Diagnostics (OBD) systems allow for monitoring of a number of drivetrain characteristics. The list of parameters that can be monitored in an OBD-II system is long (several hundred possibilities), but can include:
- Engine Coolant Temperature
- Throttle Position Voltage
- Engine RPM
- Oxygen Sensor Voltage
- Vehicle Speed
- Intake Air Temperature
- Ignition Timing
- Fuel Pressure
- Mass Air Flow Rate
- Evaporative System Status
- Cylinder Misfire
- Transmission Gear
We’ve been using DashCommand on a Google Nexus 7 tablet for a while now in the backcountry as an on-board GPS with topo map files. We were interested in using the tablet to also display some OBD-II parameters so we could monitor engine vitals and other parameters.
We turned to Palmer Performance Engineering who offers a number of hardware and software solutions that allow you to access ODB-II port information for diagnostic, monitoring, and performance purposes. We’ve used their DashCommand application (available from the iTunes App Store or from Google Play) before on an iPhone, and wanted to use it as well with our Nexus (Android-based) tablet. DashCommand is also available for Windows platforms.
DashCommand works on touch-screen devices to integrate OBD-II data monitoring and logging into a vehicle. The program allows you to create your own virtual dashboard that can include analog and digital gauges, indicator lights, and other data outputs. Combined with their DashXL dashboard editor, you can fully customize your own dashboard design on your home computer. There are also shared dash designs exchanged amongst users within Palmer’s online web forums. The graphical interface can monitor fuel economy, log OBD-II parameter readings, provide a detailed trip computer, provide real-time race track readings, display inclinometer readings showing pitch and roll, display a skid pad that can show acceleration and deceleration forces of your vehicle, and serve as a diagnostic tool for troubleshooting.
To get the OBD-II data from our vehicle port to our tablet, we used Palmer’s OBDLink MX module. This small adapter plugs into the diagnostic port and communicates via Bluetooth to the tablet. Other wired and wireless connectivity solutions are available for the various smart devices and operating systems.
In addition to polling the standard OBD-II parameters, the OBDLink MX supports SW CAN and MS CAN protocols to access proprietary GM and Ford networks. Vehicle manufacturers often monitor vehicle parameters beyond the standard CARB-specified ones. With this capability, more system data can be accessed. A full list of supported vehicle parameters is listed on Palmer’s website by vehicle make.
In addition to monitoring OBD-II parameters, the OBDLink MX will allow you to read DTCs (diagnostic trouble codes) and clear codes in the on-board computer. This is useful when maintenance or troubleshooting is needed and computer codes may be helpful with diagnosis.
Overall, the solutions from the Palmer Performance DashCommand are extremely versatile, allowing use with a smartphone, tablet, or PC for diagnostics or monitoring. They can be moved from vehicle to vehicle, and lend themselves to customization. If you want to better understand what your drivetrain is doing, you may find this to be a good solution, allowing you to create your own virtual dash gauges.