Ford is recalling more than 250,000 Ford Focus automobiles in the U.S. from model years 2012 to 2018 because the canister purge valve may malfunction, causing the engine to stall unexpectedly while driving and increasing the risk of a crash. The recall covers 255,404 vehicles that were previously repaired under an earlier recall for the same issue but were not properly fixed.

The problem involves a canister purge valve in the evaporative emissions system that can fail, leading to a sudden loss of engine power. Ford said the stall can occur without warning.

The action is a follow-up to a previous recall identified by National Highway Traffic Safety Administration number 18V735. NHTSA said the earlier repair was insufficient, prompting the new recall. Ford’s number for this action is 26S40, and NHTSA’s number for this recall is 26V369.

To fix the problem, Ford dealers will install an updated powertrain control module software free of charge. Owner notification letters are expected to be mailed July 6.

Vehicle owners can contact Ford customer service at 1-866-436-7332. The vehicle identification numbers of the affected vehicles will become searchable on NHTSA.gov on July 6.