Modern vehicle electronics are untested for EMP with no failsafe

Modern vehicles contain 70-150 electronic control units (ECUs) managing everything from engine timing and braking (ABS/ESC) to power steering and airbag deployment. These ECUs are connected by CAN bus networks with no electromagnetic shielding beyond basic EMC compliance. No automaker tests vehicles against EMP field strengths, and no NHTSA regulation requires it. A HEMP event or localized EMP weapon could simultaneously disable every vehicle in a metro area. The immediate consequence is not just immobility — it is danger. A vehicle traveling at 70 mph that loses its ECU loses power steering, ABS, electronic stability control, and engine power simultaneously. Drive-by-wire throttle and electric power steering have no mechanical backup in most vehicles manufactured after 2015. Mass multi-vehicle accidents on highways would occur at the moment of the pulse, with emergency vehicles themselves disabled. Subsequent emergency response is paralyzed because ambulances, fire trucks, and police vehicles use the same unshielded electronics. This persists because automakers design to UNECE Regulation 10 (EMC for vehicles), which tests at field strengths of 30-200 V/m — roughly 100-1,000x below HEMP E1 levels. Adding military-grade shielding to every ECU would add $500-2,000 per vehicle and 20-50 lbs of weight, which conflicts with fuel efficiency mandates. NHTSA has never issued a notice of proposed rulemaking on EMP. The auto industry's position is that EMP is a national defense issue, not a vehicle safety issue.