The National Highway Traffic Safety Administration has told Tesla Motors to turn over a wide range of detailed information as part of the agency's investigation into a fatality involving the company's Autopilot self-driving system.

In a letter to Tesla NHTSA made public Tuesday, the safety agency said it wants information for every Tesla equipped with Autopilot, ranging from the total mileage driven using Autosteer, part of Autopilot, to the total number of times the car alerted the driver to put his or her hands back on the wheel. It also sought consumer complaints to the company and reports of crashes relating to Autopilot. (Read NHTSA's letter to Tesla)

The agency also wants to know about any testing Tesla has done or is planning on the system and what changes it has made or plans to make in the next 120 days.

The nine-page letter is rather specific, for instance at one point asking the company to "provide a detailed description of the design and operation of the subject system in all crash modes, including system capability in intersection or road junction cross path collisions over the full range of the object detection (e.g. pedestrian, bicycle, various vehicle types) and closing speeds."

NHTSA put a July 29 deadline on some of the information it has requested, and an Aug. 26 deadline for the rest.

Tesla is able to collect a tremendous amount of data on individual cars because they are all equipped to wirelessly communicate with the company, which also enables them to receive software updates.

NHTSA's investigation is related to a May accident in Florida when Joshua Brown's Model S, while in Autopilot mode, failed to detect a tractor trailer up ahead that made a left turn across the divided highway. The Model S didn't hit the brakes and went under the trailer, killing Brown.

The National Transportation Safety Board also is investigating the accident. The Securities and Exchange Commission is looking into whether Tesla withheld information from investors, The Wall Street Journal reported Monday.

Since the Florida accident, two other Tesla vehicles have reportedly crashed with their Autopilot feature engaged.

Tesla did not respond to a request for comment for this article.

According to the company, the Autopilot feature is disabled by default and drivers who turn it on see an acknowledgement box on their display screen that warns Autopilot "is an assist feature that requires you to keep your hands on the steering wheel at all times."

The fatal accident has raised questions about whether consumers truly understand Autopilot capabilities. Some drivers have uploaded videos to the internet showing themselves doing other things while the car drives itself.

Tesla CEO Elon Musk is quoted in the Wall Street Journal Tuesday saying that the company has no plan to turn off Autopilot and that it is working on a blog post that will explain how drivers should use the feature.