HEM Data Products

DAWN Mini Inspector™ with TamperDetect™

Description & Purpose

DAWN Mini Inspector™ is an inspection/maintenance (I/M) tool for heavy-duty vehicles. It acquires heavy-duty, on-board diagnostic (HD-OBD) data from the vehicle’s CAN bus. HD-OBD was phased in during the 2013-2015 model years for on-road trucks. Older models and off-road vehicles are supported if the data is available on the vehicle’s network.

The TamperDetect™ algorithm uses the HD-OBD data to determine if the vehicle has been tampered to delete the emissions system. Also, Mini Inspector acquires all of the available data to assess the vehicle’s overall duty cycle and condition.

Part of a report showing a tampered vehicle

DAWN Mini Inspector is a small, easily portable solution and quick to install. All you need to do is attach the hardware to the vehicle network connector, turn on the engine, and open the smart phone app. Complete the test and view the report all within 2 minutes!

The tool is designed for federal and state governments, researchers, service technicians, and companies who resell or buy used trucks and off-road vehicles. It is important for environmental and human health to minimize diesel engine emissions and to have emission equipment operate efficiently. It is illegal to resell vehicles with tampered or deleted emissions.

Mini Inspector has been used to evaluate over 50,000 heavy and medium duty trucks. HEM Data’s online Dashboard stores the test results in a database. This enhances the analysis by comparing similar vehicles across the database.


Mini Inspector consists of three major components

  • DAWN Mini Streamer™ hardware (dongle)
  • DAWN Mini Inspector™ software
  • DAWN Mini Inspector™ Dashboard (vehicle database)


HEM Data’s Mini Streamer hardware sends data to a smart device wirelessly. The Mini Streamer has the ability to acquire all of the data available from the vehicle. The Mini Streamer hardware conveniently fits directly on the vehicle’s 9-pin J1939 connector. If the vehicle has the 16-pin J1962 connector (light-duty automobile style trapezoidal connector) or a non-standard connector, then an adapter is used. The Mini Streamer acquires both J1939 and J1979 data.

J1939 Mini Streamer™

DAWN Mini Inspector Software

DAWN Mini Inspector is supported on both an iPad and iPhone. The app receives the data from the Mini Streamer hardware using a direct WiFi connection. The app displays real-time information to the user as the test is progressing. The app sends the data to the Dashboard when the smart device has internet access. The analyzed results are conveniently displayed in the app for quick feedback.

Parameters table showing live data

The screenshot above shows the live values table. The screenshot below shows all active, previous, and pending trouble codes on the vehicle.

Active, previous, and pending trouble codes

DAWN Mini Inspector Dashboard

The DAWN Mini Inspector Dashboard analyzes both J1939 and J1979 data. This is important since J1939 Diagnostic Messages (DMs) equivalents are reported differently in J1979.

Using TamperDetect™, the dashboard analyzes whether the vehicle’s OBD system and emission control equipment have been tampered or deleted. The vehicle report is available directly from the app.

J1939 Mini Logger™ OBD Mini Logger™ DAWN Telematics™ DAWN™ Software ADAQ Mini™ DAWN Dashboard™