Accessing comprehensive data from your KTM 390’s OBD2 port can be crucial for diagnostics and performance tuning. While OBD2 requests provide specific data points, understanding the full scope of information available on the CAN-BUS can offer deeper insights. This article explores whether all data accessible via OBD2 requests is also present in the regular CAN-BUS traffic of a KTM 390.
OBD2 (On-Board Diagnostics) is a standardized system that allows external devices to access diagnostic information from a vehicle’s engine control unit (ECU). Using an OBD2 adapter, like an ELM327, you can request specific data points, such as intake air temperature (IAT), RPM, and more. These requests and responses utilize specific CAN-BUS IDs and formatted messages. For instance, requesting the IAT on a KTM 390 might involve a 7DF request ID and a 7E8 response ID containing the temperature value.
However, the continuous data stream on the CAN-BUS, even without OBD2 requests, contains a wealth of information about the vehicle’s various systems. This raises the question: does the regular CAN-BUS traffic include all the data that can be requested via OBD2?
In the case of the KTM 390 (specifically the 2017 model with a 500kbps CAN-BUS), some values, like RPM, are readily visible in both OBD2 responses and the regular CAN-BUS traffic. However, other data points, such as IAT, might not be continuously broadcast on the CAN-BUS.
It’s important to understand that the ECU actively manages the data transmitted on the CAN-BUS. Certain values might only be transmitted when a specific condition is met or when requested by another module within the vehicle’s network. This optimization reduces bus load and ensures efficient communication.
Therefore, while some OBD2 data points might be present in the regular CAN-BUS traffic, it’s not guaranteed that all data will be available without specific requests. For instance, the IAT might only be calculated and transmitted when requested via OBD2 or when required by the engine management system.
While analyzing raw CAN-BUS data can be complex, understanding the data structure and identifying specific CAN IDs associated with desired parameters is key to extracting valuable information. This involves decoding the individual bytes within CAN frames and potentially applying calculations based on sensor calibrations.
In conclusion, while the KTM 390’s CAN-BUS contains valuable data, not all OBD2 accessible information is continuously broadcast. Some data points, like IAT, may require specific requests to be transmitted. Developing a device that passively listens to the CAN-BUS might require incorporating OBD2 request functionality to guarantee access to all desired data points. Alternatively, consider utilizing existing OBD2 libraries and tools to simplify the data acquisition process.
