Publicly, Congress has done little on the Toyota recalls since a series of tense hearings two months ago. Behind the scenes, however, Toyota Motor Corp. has been waging a lobbying campaign to reassure lawmakers and shore up its brand while key members of Congress have been crafting broad legislation on auto safety in response to the recalls.

A draft of the legislation from April would impose several new requirements on automakers. The draft bill orders changes to vehicle braking standards, mandates vehicle data recorders that could be read by universal readers, and requires automakers to contribute information to a federal database intended to serve as an early-warning system for defects.