However, the agency won't identify specifically what issues it has discovered in Tesla cars following the software patch aimed at fixing the flaw that promoted a widespread recall. The agency is also looking into the measures that Tesla pushed to remedy Autopilot safety concerns, but weren't originally detailed as part of the recall communication. "This investigation will consider why these updates were not a part of the recall or otherwise determined to remedy a defect that poses an unreasonable safety risk," says the agency in a memo (PDF) released earlier today. The latest NHTSA investigation comes at a crucial juncture for Tesla. Sales and profits have taken a steep plunge, experts continue to question the safety measures in place, and lawsuits over its advanced driver assistance systems (ADAS) are piling up, while CEO Elon Musk continues to push autonomy as the future of the company.