Mass. Gen. Laws ch. 93K, § 2
(c)
(2) Any diagnostic tool or information necessary to diagnose, service or repair a motor vehicle that a manufacturer sells to an independent repair facility in a manner and on terms and conditions more favorable than the manner and the terms and conditions which a dealer obtains the same diagnostic tool or information necessary to diagnose, service or repair a motor vehicle, shall also be offered to the dealer in the same manner and on the same terms and conditions as provided to such independent repair facility.
A manufacturer that sells to an independent repair facility any diagnostic tool necessary to diagnose, service or repair a motor vehicle and such diagnostic tool communicates with the vehicle using the same non-proprietary interface used by other manufacturers, the manufacturer delivering such a diagnostic tool shall be prohibited from requiring any dealer from continuing to purchase that manufacturer's proprietary tool and interface unless such proprietary interface has a capability not available in the non-proprietary interface.
(d)
(ii) an onboard diagnostic and repair information system integrated and entirely self-contained within the vehicle, including, but not limited to, service information systems integrated into an onboard display; or (iii) a system that provides direct access to onboard diagnostic and repair information through a non-proprietary vehicle interface, such as ethernet, universal serial bus or digital versatile disc. Each manufacturer shall provide access to the same onboard diagnostic and repair information available to their dealers, including technical updates to such onboard systems, through such non-proprietary interfaces as referenced in this paragraph. Nothing in this chapter shall be construed to require a dealer to use a non-proprietary vehicle interface specified in this paragraph, nor shall this chapter be construed to prohibit a manufacturer from developing a proprietary vehicle diagnostic and reprogramming device; provided, however, that:
(i) the manufacturer also complies with this paragraph; and (ii) the manufacturer also makes this device available to independent repair facilities upon fair and reasonable terms and otherwise complies with subsection (a).
Notwithstanding anything in the preceding paragraph, motor vehicle owners' and independent repair facilities' access to vehicle on-board diagnostic systems shall be standardized and not require any authorization by the manufacturer, directly or indirectly, unless the authorization system for access to vehicle networks and their on-board diagnostic systems is standardized across all makes and models sold in the Commonwealth and is administered by an entity unaffiliated with a manufacturer.