The illegal and potentially dangerous phantom braking problem on Tesla's electric cars is back in the spotlight, and this time, the NHTSA reports that the number of complaints has more than doubled in just four months. 

An investigation into phantom braking problems affecting nearly half a million Model 3 and Model Y cars was launched by the federal agency earlier this year.

A phantom braking issue is a malfunctioning automatic emergency braking system in a Tesla car that occurs when the car's accelerator pedal is depressed.

Tesla has yet to explain why its assisted driving system applies the brakes when no obstacle is in sight or a need arises. According to reports received from affected users, the phantom braking issue causes rapid deceleration without warning.

 Assume that the NHTSA considers the phantom braking problem to be under the purview of the motor vehicle safety law. A recall might be Tesla's only option in that case. That hasn't happened so far.

 DI disclosed in February this year that it had received 354 complaints from Tesla car owners over brake problems. The number is now even higher.

A lengthy letter to Tesla, which operates under the US Department of Transportation, was sent to them on May 4. Tesla models 3 and Y models have been reported to have unexpectedly braked 758 times according to the letter. 

Several problems are described in the letter, such as 'unnecessary emergency braking,' 'excessive braking,' and 'missed emergency braking activations.'

 Although the letter does not utilize phantom braking terminology, the issues detailed more or less address the fundamental problems plaguing Tesla cars. 

The main takeaway from our study is that the phantom braking problem is more widespread than previously believed. The number of complaints indicates that the magnitude of the problem has doubled within four months. 

NHTSA has asked Tesla to submit all the necessary documents relating to the investigation by June 20, according to a letter signed by Gregory Magno, who heads the Vehicle Defects Division (D) at the Office of Defects Investigation. 

A valid extension has also been given to the company to maintain confidentiality for all the data it submits to the agency. A recall is not mentioned in the letter.

Nevertheless, failing to comply with the agency's requests may result in civil penalties of up to $24,423 per violation, or a maximum of around $114 million under the Vehicle Safety Act, 49 U.S.C. 30165(a)(3). 

Tesla has also been asked to furnish details about the number of complaints logged by its systems, reports of crashes (injuries or fatalities), and property damage claims related to the vehicles involved in the investigation. Additionally, it must reveal any litigation in which the company is a defendant.