Skip to content
English
Contact us
  • There are no suggestions because the search field is empty.

Why am I getting Odometer/Run Hours readings from engine on one asset and not getting on the other?

Even though two similar assets are equipped with the same telemetry device, the data collected may differ between them. This variation occurs due to several factors related to vehicle design, communication protocols, and data access restrictions.

Why Does This Happen?

Some vehicles do not allow certain types of data to be collected by an OBD (On-Board Diagnostics) device. Despite the standardized nature of OBD-II systems, manufacturers implement unique configurations that affect the availability and accessibility of telemetry data. Below are key reasons why data differences may occur:

  1. Manufacturer and Model Variations
    Even within the same brand or model range, differences in production years, trim levels, and regional specifications can lead to variations in the data exposed to the telemetry device.

  2. OBD-II Protocol Differences
    Vehicles may use different OBD-II communication protocols, such as CAN, J1850, and ISO 9141-2. These protocols influence how data is transmitted, and which parameters are accessible to external devices.

  3. ECU Restrictions
    The Electronic Control Unit (ECU) of a vehicle manages access to critical data points. Some manufacturers restrict access to certain data for security, proprietary, or regulatory reasons, making it unavailable for third-party telemetry devices.

  4. Aftermarket Modifications
    If a vehicle has undergone aftermarket modifications, such as ECU tuning or custom sensor installations, it might transmit different data or block specific readings compared to a factory-standard version of the same model.

  5. Device Compatibility and Firmware Differences
    While OBD devices are designed to be compatible with multiple vehicles, not all devices support every manufacturer’s data structure. Additionally, variations in firmware versions can impact the ability of the telemetry device to decode and interpret certain vehicle parameters.

Conclusion

Even when using identical telemetry devices, variations in data collection can occur due to manufacturer-specific configurations, protocol differences, ECU restrictions, modifications, and device compatibility. Understanding these factors can help fleet managers, technicians, and data analysts make informed decisions when deploying and interpreting vehicle telemetry solutions.