The National Highway Traffic Safety Administration (NHTSA) has issued a formal request for detailed information from Tesla for the agency’s investigation into the recent Model S fires.

NHTSA is investigating “underbody deformation in the Model S resulting from impacts with road debris including, but not limited to, consequent intrusion into the battery compartment and associated risks to motor vehicle safety.” The request for information covers 13 categories, including full details of the fire incidents, any consumer complaints or other claims, details of the engineering and design of the battery packs, and any tests that have been done relating to the “alleged defect.”

Tesla has until mid-January to respond, although it’s safe to assume that the company will want to get the process over with as quickly as possible.

Meanwhile, those efficient Germans have already performed their own investigation, and given Tesla’s electric sedan a clean bill of health.

Tesla recently provided the German Federal Motor Transport Authority (Kraftfahrt-Bundesamt, or KBA) with data and additional information regarding the post-crash fire incidents. The KBA is the German authority in charge of motor vehicle regulation, and has the power to perform investigations and require recalls.

The KBA shared the results of its investigation in a brief note sent to Tesla this week, saying, “no manufacturer-related defects could be found. Therefore, no further measures under the German Product Safety Act are deemed necessary.”

Sources: Tesla, Green Car Congress