A key element of the U.S. government's investigation of Toyota Motor Corp <7203.T> electronic throttles and other systems found no defects beyond what is known to explain crashes blamed on unintended acceleration, the Transportation Department said on Tuesday.

Findings presented to Congress on the agency's review of selected Toyota electronic data recorders are preliminary and could end up bolstering the automaker's contention that mechanical and equipment problems behind huge recalls and possible driver error are to blame, not vehicle electronics.

The National Highway Traffic Safety Administration (NHTSA) said it drew no conclusions from the examination of 58 recorders as part of its multi-layered investigation to see if electronic throttles may have a glitches that in rare cases can cause unexpected surges or even wild acceleration.

In more than half of the black boxes examined, there was no indication that drivers even applied brakes and in other cases partial braking was noted.

Reviewing event data recorders is one small part of the government's effort to get to the bottom of unintended acceleration in Toyota vehicles, said Transportation Department spokeswoman Olivia Alair.

At this early stage period in the investigation, engineers have not identified any new safety defects, Alair said.

Toyota, which recalled more than 8 million cars worldwide this year and last over unintended acceleration related to sticking gas pedals and loose floormats that can jam the accelerator, has said its throttle systems are sound.

Toyota had no immediate comment on the findings.

Congressional committees are conducting parallel investigations and Toyota faces lawsuits, including an amended federal case in California that alleges the Japanese automaker ignored evidence of acceleration problems for most of the past decade and failed to remedy the problem.

Toyota was fined $16 million this year for failing to disclose the so-called sticky pedal problem to regulators.

In the data recorder examination, NHTSA examined recorders from vehicles involved in crashes whose drivers had alleged unintended acceleration or raised the possibility of unwanted acceleration.

Of the 58 recorders studied, 35 showed no braking -- which could indicate driver error. Others revealed partial braking and there was no measurable data in five cases.

Since 2000, electronic throttle control was cited in complaints associated with 52 Toyota crashes that reportedly killed 62 people, government auto safety records show.

Additional findings from the government-led investigation of Toyota, that also includes U.S. space agency experts, are not due until later this year.

A comprehensive report involving an independent scientific panel is not expected until 2011.

(Reporting by John Crawley; editing by Andre Grenon and Carol Bishopric.)

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