American diesel fuel could be hurting fuel pumps produced by Robert Bosch, LLC, and causing a range of automobiles from a quantity of automakers, namely Stellantis and BMW, to shed energy, the National Highway Traffic Safety Administration (NHTSA) reports.

As a outcome, the regulator’s Office of Defects and Investigations (ODI) announced nowadays that it has upgraded its investigation into the components in query, launching an engineering evaluation and searching into producers who employed them. However, it has not but essential any recall campaigns to be launched.

The ODI initial opened its investigation into automobiles with the fuel pumps in query in October 2021, following allegations of stalling in 2019-2020 Ram 2500, 3500, 4500, and 5500 heavy-duty trucks equipped with the six.7-liter Cummins turbodiesel engine.

Read: Daimler Recalling Loads Of Diesel Vehicles, Including 260,000 Sprinter Vans

Since then, each carmakers filed recalls connected to the fuel pump, with BMW indicating that an unexpected reaction in between U.S. diesel and the pumps’ internal elements was major to enhanced slip. That in turn led to grinding and put on that could send particles downstream, and gum up the operates.

In a document produced public Tuesday, the ODI mentioned that the engineering evaluation will appear into regardless of whether the very same situation that impacted the BMW models is the very same for the Ram automobiles, and other individuals.

The investigation is searching into the internal pump elements that are connected to stalling and loss of energy. It will also seek to determine the total car quantity connected with the situation and will decide regardless of whether that poses a security threat worthy of a recall.

Autonews reports that, in addition to the heavy-duty Ram trucks listed above, the ODI’s probe also covers the 2014-2022 Ram 1500, the 2021-2022 Jeep Gladiator, the 2014-2020 Grand Cherokee, and the 2020-2022 Wrangler. In addition, the 2014-2018 BMW 328D, the 2014-2016 535D, and the 2015-2017 X3 could also be implicated. In total, much more than 490,000 could be impacted by this investigation.