Tribovoltaic nanogenerators, capable of generating direct current through friction-induced carrier migration, represent a promising frontier in self-powered sensing. However, conventional semiconductor materials face critical limitations in mechanical properties and cost-effectiveness in real applications. Here, an amorphous hydrogenated carbon-based multifunctional tribovoltaic coating (M-TC) is introduced by physical‑vapor deposition that simultaneously delivers semiconducting functionality and exemplary tribological robustness. Comprehensive ball-on-disk tribological tests revealed a strong correlation between tribological behavior and electrical output, with the M-TC exhibiting an ultralow friction coefficient of 0.066 under self-lubricating conditions and a notably high peak power density of 1.18 kW m−2. First-principles simulations further confirmed the coating's exceptional structural stability and efficient electron transport capabilities at the nanoscale. Practical integration of the M-TC into bearing systems demonstrated significantly reduced friction torque, minimized vibration, and effectively suppressed temperature rise, validating its real-world advantages. Moreover, spectral analysis of the generated electrical signals enabled robust and real-time monitoring of bearing anomaly detection with exceptional sensitivity (linearity R2 = 0.9997). This study significantly advances multifunctional tribovoltaic coatings, providing a viable pathway toward the development of components with integrated protective and sensing functionalities suitable for next-generation intelligent manufacturing systems.