Geometry-Anchored Paired Component-to-System Order Analysis with Falsification-Controlled Interpretation for End-of-Line Noise, Vibration, and Harshness of Electric-Vehicle Drivetrains

Component-level vibration tests are performed before final assembly, but how their order-domain signatures relate to later drive-unit end-of-line (EOL) noise, vibration, and harshness (NVH) remains uncertain. This study links two pre-assembly component-test states to four EOL channels for 107 electric-drivetrain units using exact genealogy. The paired state-difference spectrum, Δ(B − A), identified contiguous shaft-synchronous regions associated with later EOL nonconformity, while high-order associations to the fourth mesh-family harmonic (H4) formed an approximately one-order-spaced modulation comb. A four-feature topology model achieved area under the receiver operating characteristic curve (ROC-AUC) of 0.742–0.753 across random and process-grouped validation, close to PCA(10) on the full Δ-spectrum (0.785–0.788). A falsification-controlled kinematic audit rejected an attractive grid-derived carrier assignment. A secondary archive of 3157 machine-readable coordinate-metrology records provided a geometry anchor: in a predeclared 30-day one-to-one subset, the sixth circumferential pitch-error harmonic of the 28-tooth component family was strongly associated with the corresponding State-B symmetric sideband family (n = 14, Spearman ρ = −0.908, and FDR-adjusted q = 8.8 × 10−5) and remained directionally consistent across traceability and timing sensitivity analyses. Direct geometry-to-EOL H4 associations did not survive multiplicity correction. The results support staged geometry-to-component and component-to-EOL relationships without claiming complete same-unit causal mediation.