(Reuters) - Voters in Massachusetts on Tuesday overwhelmingly passed a ballot measure forcing automakers to provide expanded access to mechanical and electronic repair data and allow independent shops to repair increasingly sophisticated technology. The decision delivers the first significant win in a fight over who will control the $390 billion U.S. auto data aftermarket in the digital age. Unprecedented advancements in modern cars and crash avoidance systems such as automatic braking have prompted many automakers to limit information and warranties to only parts and repairs from authorized dealers to ensure safety and privacy. They say such data is complex and sensitive, and argue that repairs to modern cars require extensive training by those with proprietary technology. Independent repair groups have rebuked those restrictions as an attempt to seize control of the lucrative repair market and a way to force consumers into more expensive manufacturer-affiliated dealer shops. They are also concerned by automakers increasingly pushing for wireless repair data transfers, which will limit third-party access. “This referendum...means that despite advances in technology, owners will be able to have their repair data shared directly with their trusted independent shops,” Bill Hanvey, president and CEO of the Auto Care Association said in a statement, adding the group worked with cybersecurity experts to ensure privacy during data transfers. Under the state’s ballot measure, approved by 75% of voters, on-board diagnostic and mechanical data will have to be made available via an open-platform app for 2022 vehicle models and beyond. Automakers including General Motors, Ford Motor Co, Toyota Motor Corp, Honda Motor Co and Nissan Motor Co had opposed the Massachusetts ballot initiative. John Bozzella, President and CEO of the U.S. industry trade group Alliance for Automotive Innovation in a statement said the measure presented real risks to the security of customers’ vehicles. “Automakers have made available all the diagnostic and repair information that is needed to service a vehicle safely and securely,” Bozzella said.