Diagnostic Trouble Codes (DTCs)

Diagnostic Trouble Codes (DTCs) are used by automobile manufacturers to diagnose problems related to a vehicle or trailer. These codes are transmitted through the vehicle port to identify and communicate to technicians where and what onboard problems exist. Using compatible cable and device types, Samsara can read data from the OBD-II port (light duty vehicles), the J1939 port (in heavy duty vehicles), and the J1587 port (in trailers).

For OBD-II systems, the first number in the DTC indicates whether the code is an SAE generic code or is specific to the vehicle manufacturer. The remaining three numbers provide information regarding the specific vehicle system and circuit. The following figure illustrates the breakdown of a typical code sourced from the OBD-II:

The Samsara Vehicle Gateway (VG) plugs directly into the OBD-II or the J1939 port of a vehicle and can thus relay any information regarding any DTC directly to the Samsara dashboard.

When you install the AG52 using a CBL-AG-BABS or CBL-AG-BPLC cable type, the AG52 plugs in directly into the 5-pin connector of the Trailer ABS power line and can relay information regarding the trailer ABS status.

Both the VG and AG52 can raise Fault Code Alerts if a DTC occurs.

While Samsara can identify which DTCs a vehicle or trailer reports, the dealership or manufacturer of the vehicle is your best resource for interpreting and addressing a specific DTC.