The highest federal auto security regulator despatched two letters to Tesla this week elevating questions concerning the firm’s driver-assistance software program techniques and instructing the carmaker to offer fuller info.

The regulator, the Nationwide Freeway Site visitors Security Administration, is trying into why Tesla didn’t challenge a recall final month when it up to date software program known as Autopilot to enhance its skill to identify stopped emergency automobiles corresponding to police vehicles and fireplace vehicles.

The company additionally ordered Tesla to offer information concerning the software program that the corporate calls Full Self-Driving and expressed concern that Tesla could also be stopping clients from sharing security info with the company.

The strikes recommend that NHTSA is taking a more in-depth have a look at Tesla’s driver-assistance options and the hole between their names and their skills.

“I respect now that NHTSA is taking some steps ahead, however it ought to have occurred earlier than,” Jennifer Homendy, chair of one other federal company, the Nationwide Transportation Security Board, mentioned in a current interview. “It must occur extra shortly, as a result of in any other case you danger folks’s lives.”

The security board investigates the causes of vehicle, practice, airplane and different transportation accidents however has no regulatory energy over producers, as NHTSA does.

Concern about Autopilot — a system of cameras and different sensors that may steer, brake and speed up with little enter from a driver — has been rising as a result of the expertise generally fails to detect objects or different automobiles. Regardless of its identify, Autopilot doesn’t allow autonomous driving, and Ms. Homendy’s company has mentioned the expertise lacks safeguards to make sure that drivers stay alert and in management.

Full Self-Driving is a extra superior system that Tesla has allowed a small set of homeowners to check on public roads. Nevertheless it, too, just isn’t in a position to pilot a automobile with out lively engagement by a human driver.

In August, NHTSA opened a proper investigation into 12 crashes during which Tesla vehicles working in Autopilot mode didn’t detect stopped emergency automobiles that had their lights flashing in low gentle. One accident killed a passenger. Different Autopilot crashes have accounted for 10 deaths since 2016, in response to information compiled by NHTSA.

Tesla and its chief government, Elon Musk, have mentioned Autopilot just isn’t flawed, insisting that it makes vehicles much safer than others on the road, and so they have dismissed criticism of the corporate’s design course of. However NHTSA is now questioning whether or not Tesla’s software program refinements sidestep regulatory scrutiny.

Usually, automakers challenge recollects and house owners take their vehicles to sellers for repairs or updates. However Tesla can modify its vehicles by sending them software program updates over the web.

In a letter on Tuesday, NHTSA reminded Tesla that federal regulation requires automakers to provoke formal recollects in the event that they discover defects that pose a security danger, in order that each house owners and NHTSA are knowledgeable of the fixes.

“Any producer issuing an over-the-air replace that mitigates a defect that poses an unreasonable danger to motorcar security is required to well timed file an accompanying recall discover to NHTSA,” the company mentioned in a single letter to Tesla.

NHTSA advised the corporate to offer detailed info on a software program replace, despatched in late September, that changed Autopilot and enhanced its skill to detect emergency lights.

The letter advised Tesla to state whether or not it intends to challenge a recall associated to the replace and, if not, any authorized or technical causes that it declines to take action.

That letter was despatched by Gregory Magno, the chief of NHTSA’s car defects division in its workplace of defects investigation, to Eddie Gates, Tesla’s director of discipline high quality.

In a separate letter to a senior Tesla legal officer, NHTSA ordered the corporate to reveal the variety of house owners who’ve been given Full Self-Driving software program as a part of a beta take a look at, to offer copies of any nondisclosure agreements it has had these testers signal and to clarify whether or not the phrases would forestall house owners from reporting any security considerations to NHTSA.

As a result of shoppers are an vital supply of data to the company, “any settlement which will forestall or dissuade contributors within the early-access beta launch program from reporting security considerations to NHTSA is unacceptable,” the company mentioned. “Furthermore, even limitations on sharing sure info publicly adversely impacts NHTSA’s skill to acquire info related to security.”

Tesla didn’t reply to emails requesting remark for this text.