SAE J973™ MAR2026 (R) specifies design and evaluation procedures for distributorless battery ignition systems used in automotive, marine, motorcycle, and utility engine applications. The standard covers test-bench measurements for available, open-circuit, and loaded secondary voltage; spark current, duration, voltage, and energy under Zener loads; peak and average primary current; primary energy; secondary voltage risetime; IGBT collector voltage; timing lag; and dwell time.
It also defines ignition system configurations, system loads, test equipment requirements, bench circuit arrangements, measurement procedures, and suggested parametric test conditions across specified ambient temperatures and battery voltages. The procedures are intended for bench testing only and exclude direct measurements on engines or vehicles and battery ignition systems used in aircraft applications.
Application Scope: Distributorless battery ignition system design verification and performance evaluation for automotive, marine, motorcycle, and utility engine applications using controlled test-bench measurements.
