What NHTSA says the defect is
Mazda North American Operations (Mazda) is recalling certain 2014-2015 Mazda6 and 2014-2016 Mazda3 vehicles. Water could possibly enter the brake caliper causing the parking brake actuator shaft to corrode and possibly bind.
The risk NHTSA states
If the parking brake actuator shaft binds, the parking brake may not engage or disengage fully. If the parking brake does not engage properly, the vehicle may move unexpectedly if it is parked on a slope, increasing the risk of a crash.
The remedy NHTSA states
Mazda will notify owners, and dealers will check the parking brake actuator shafts, replacing any that are corroded, free of charge. Remedy parts are currently unavailable. Interim notices informing owners of the safety risk were mailed August 24, 2017. Owners will receive a second notice when remedy parts become available. Owners may contact Mazda customer service at 1-800-222-5500. Mazda's number for this recall is 1217F.
Campaign 17V393000 · reported to NHTSA 22 June 2017 · Read it on nhtsa.gov →