How does my device report odometer values?

Question: What causes mileage discrepancies between what odometer value I see on my vehicle dashboard and what odometer value is shown for the vehicle in the GPS system? There can be several sources of odometer readings in your vehicles: GPS Odometer The default source for odometer readings is a device-oriented mileage based only on GPS-based distance data collected from the device. Each GPS tracking device tracks a cumulative distance from when the device was initially activated. This value is not an actual odometer because the device does not communicate with the vehicle's Engine Control Module (ECM). In order to correlate this value with the actual odometer of the vehicle, we get the initial odometer of the vehicle at the time of installation, and we add the device's cumulative distance to that. Over time, the total odometer we report, based on distance values collected from the device, may differ from the…