WASHINGTON — The Obama administration came under pressure Wednesday to disclose more information about its investigation of Toyota Motor Corp., with congressional Republicans questioning whether officials are withholding data that could favor Toyota in some crashes, The Wall Street Journal reported.

Rep. Joe Barton of Texas, the senior Republican on the House Energy and Commerce Committee, sent a letter to the administration's top auto-safety regulator pressing for a detailed update on the government's inquiry into Toyota crashes linked to sudden acceleration.

Barton sought information about crash data that, according to a Wall Street Journal article published last week, indicate in dozens of crashes, the driver was jamming on the gas pedal instead of the brakes, suggesting driver error.

The Journal cited people familiar with the crash-data test results. The Transportation Department, which has been examining the data, has declined to comment on the article.

The letter to David Strickland, head of the Transportation Department's National Highway Traffic Safety Administration, was also signed by Energy and Commerce Committee members Reps. Ed Whitfield (R., Ky.) and Michael Burgess (R., Texas).

"It is important for us to know whether NHTSA has EDR data showing that some incidents of reported sudden unintended acceleration were the result of pedal misapplication," the congressmen wrote in the letter. EDR stands for event-data recorders, also known as "black boxes," that are embedded in cars and record crash information.

Spokeswomen for Strickland and the Transportation Department couldn't immediately be reached for comment.

The Republican lawmakers pointed out in the letter that the House is expected to vote soon on a far-reaching vehicle-safety bill that responds to the Toyota recalls. The legislation would mandate certain safety features in vehicles, increase the maximum amount that car makers could be fined for safety lapses and require public disclosure of vehicle-design information.