Safety regulators are evaluating whether Ford’s measures to fix a fuel injector problem is adequate.

The National Highway Traffic Safety Administration (NHTSA) opened an investigation into Ford Motor Company over its effects to recall nearly 43,000 Bronco Sport and Escape SUVs. The recall in question (NHTSA recall number 23V-187, Ford recall number 24S16) affects 2022-2023 Bronco Sport models built at the Hermosillo plant in Mexico between October 17, 2022 and January 13, 2023, as well as Escapes built at Ford’s Louisville assembly plant between October 17 and December 15, 2022.

Ford’s recall centers around 1.5-liter-equipped versions of the two SUVs, with fuel injectors that may crack and allow a high-rate leak which could travel out of the injectors and onto hot surfaces, triggering a fire. The NHTSA investigation resume published Friday said the Office of Defects Investigation (ODI) will review Ford’s recall remedy to update the engine control software and install a drain tube — but not replace the fuel injectors — is sufficient.

The investigation resume notes, “[Ford’s] engine control software update will detect a pressure drop in the fuel rail providing a ‘seek service’ message within the vehicle’s instrument cluster, as well as invoke a strategy to disable the high-pressure fuel pump, de-rate engine power output, and reduce temperatures of possible ignition sources in the engine compartment. The drain tube will allow fuel to drain from the cylinder head hole to the ground below the vehicle away from surfaces which may initiate combustion. The recall remedy does not include replacement of the cracked fuel injector.”

Speaking to ABC News, the automaker did say it would extend warranty coverage for cracked fuel injectors, so owners who do experience the problem will get replacements. It is not replacing injectors on all vehicles under the recall and instead implementing this preventative measure because it is confident the software and drain tube repairs “will prevent the failure from occuring and protect the customer.” It also notes it is working with the NHTSA during its investigation.

Ford Motor Company further says the problematic injector design and accompanying engine software only went into production October 17, 2022, and was taken out of production on January 13, 2023. Of the 42,652 impacted vehicles included in the recall campaign (22,270 Bronco Sports and 20,382 Escapes), the automaker estimates only 1% may actually have cracked fuel injector issues that need to be remedied.

A similar recall, with the same remedy, went out in late 2022 (NHTSA number 22V-859), impacting nearly 522,000 Bronco Sport and Ford Escape models equipped with the 1.5-liter EcoBoost engine.