The rapid evolution of automotive electronics toward software-defined vehicles has intensified the demand for highly reliable and fault-tolerant embedded processing systems. Automotive zonal controllers, which consolidate multiple vehicle functions into centralized computing units, must meet stringent safety standards such as ISO 26262 while operating under harsh environmental conditions. This paper presents a comprehensive and theoretically grounded exploration of fault-tolerant dual-core lockstep architectures as a viable solution for ensuring high reliability in automotive zonal controllers. Drawing exclusively from existing literature, the study synthesizes key techniques including lockstep execution, hybrid error detection mechanisms, embedded debug-based resilience, and soft error mitigation strategies. The analysis examines the architectural principles of dual-core lockstep systems, their implementation challenges, and their effectiveness in detecting transient and permanent faults, particularly those induced by radiation and environmental stress. Furthermore, the paper investigates advanced enhancements such as dynamic lockstep, triple-core lockstep extensions, and reconfiguration-based recovery mechanisms. A detailed methodological framework is developed to conceptually evaluate system resilience, performance trade-offs, and compliance with automotive safety integrity levels. The findings suggest that while lockstep architectures significantly enhance fault detection coverage, they introduce challenges related to power consumption, area overhead, and system latency. The discussion critically evaluates these trade-offs and identifies future research directions, including adaptive fault tolerance, AI-driven resilience mechanisms, and scalable architectures for next-generation automotive platforms. This work contributes to the academic and industrial discourse by offering a unified perspective on fault-tolerant processor design for safety-critical automotive applications.

Fault tolerance, Lockstep architecture, Automotive zonal controllers, Soft error mitigation

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