System and method for diagnosing vehicle power distribution using battery-terminal and ecu-reported voltage correlation

Abstract

A system and method are disclosed for diagnosing vehicle electrical power distribution conditions includes digital computing device that receives diagnostic data from an on-board diagnostic interface device, the diagnostic data including at least one control-module-reported supply voltage parameter. The computing device also receives battery-terminal voltage measurements from a voltage measurement device coupled directly to terminals of a vehicle battery, the battery-terminal voltage measurements being independent of vehicle electronic control units. The digital computing device correlates the control-module-reported supply voltage parameter with the battery-terminal voltage measurements over time to determine whether a voltage anomaly originates at the battery or along a downstream power distribution path supplying one or more electronic control units. In example embodiments, the system buffers voltage data, distinguishes transient fluctuations from sustained deviations, optionally applies adaptive alignment techniques, compares voltage behavior across multiple control modules, and generates diagnostic outputs including visual wiring representations identifying suspected power distribution elements.