By David Shepardson

WASHINGTON (Reuters) - The chairman of the U.S. Senate committee that oversees auto safety issues wrote Tesla Motors Inc Chief Executive Elon Musk on Thursday, asking the automaker to brief the committee on a fatal May 7 crash involving its Autopilot software.

Senator John Thune, a South Dakota Republican who heads the U.S. Senate Committee on Commerce, Science, and Transportation, asked the automaker to brief the committee by July 29 on the accident and Tesla's response to it, according to the letter seen by Reuters.

The request from Thune, signaling increased scrutiny on the Silicon Valley heavyweight, came as Consumer Reports magazine urged Tesla to disable the automatic steering function on its electric vehicles due to the crash, which U.S. safety regulators are investigating.

The magazine, which has 8 million subscribers and influences buyer decisions with its annual vehicle ratings, also asked Tesla to change the name of its Autopilot driving-assist system to fully test safety systems before public deployment.

Thune wrote that he was interested in hearing about Tesla's efforts to ensure its technology is "deployed safely." He added that "manufacturers must educate consumers not only about their benefits but also their limitations."

A Tesla spokeswoman said she had not seen the letter and did not have an immediate comment.

Separately, Musk said in a tweet that a recent crash in Pennsylvania, in which the driver said he was in Autopilot mode when he crashed, was not due to the software.

"Onboard vehicle logs show Autopilot was turned off in Pennsylvania crash. Moreover, crash would not have occurred if it was on," Musk wrote.

The U.S. National Highway Traffic Safety Administration (NHTSA) said last week that it was reviewing the Pennsylvania crash. The Pennsylvania State Police said on Tuesday that the Tesla driver, Albert Scaglione of Farmington Hills, Michigan, had been charged with careless driving.

Consumer Reports said the Autopilot name promotes "a potentially dangerous assumption" that the vehicle is capable of driving on its own.

But California-based Tesla defended the product and its name, saying Autopilot functions like the systems that airplane pilots use when conditions are clear. "The driver is still responsible for, and ultimately in control of, the car," the company said.

NHTSA is investigating the May 7 crash and death in Florida of a Model S driver who was using Autopilot.

Consumer Reports said it wants Tesla to require drivers to keep their hands on the wheel as part of an updated driver-assist system.

"By marketing their feature as ‘Autopilot,’ Tesla gives consumers a false sense of security," said Laura MacCleery, vice president of consumer policy and mobilization for Consumer Reports.

"We’re deeply concerned that consumers are being sold a pile of promises about unproven technology. ‘Autopilot’ can't actually drive the car, yet it allows consumers to have their hands off the steering wheel for minutes at a time."

Tesla said that while it appreciated well-meaning advice, the company would make its decisions "on the basis of real-world data, not speculation by media."

Tesla shares were little changed on Thursday, trading at $222.90.

Tesla, in a June blog post about the Florida crash, described Autopilot as being in a "public beta phase" and said customers have to opt in before activation.

Earlier this week, NHTSA said it wants records of how many times the system told drivers to put their hands on the wheel.

Tesla said on Tuesday its autosteer software, the steering function in Autopilot, was enabled during a Sunday crash involving a Model X in Montana. Tesla said data suggested "the driver’s hands were not on the steering wheel."