DETROIT — Toyota Motor Corp has discovered and fixed a bug in the software that reads data from crash recorders and informed U.S. safety regulators of the problem in June, executives said Monday.
The disclosure comes as the world's largest automaker battles to distance itself from a series of recalls this year that damaged its reputation for quality and raised concern about reports of unintended acceleration in its vehicles.
The National Highway Traffic Safety Administration said last month that it had found no evidence of new defects based on an examination of 58 event data recorders popularly known as ‘'black boxes” — from Toyota vehicles.
In more than half of the recorders that U.S. safety regulators examined, there was no indication that drivers applied brakes.
Toyota has said repeatedly that it has found no evidence of any fault with electronics or throttle controls on its vehicles that would necessitate further safety action.
Since last year, the company has recalled more than 8 million vehicles worldwide for unintended acceleration related to sticking gas pedals and loose floormats that could jam the accelerator.
Toyota has also been cooperating with a U.S. government-led investigation of its safety systems that has included U.S. space agency critics.
But safety advocates and lawyers for Toyota owners and crash victims have challenged whether the automaker's crash recorders are reliable as evidence in that probe.
Takeshi Uchiyamada, the Toyota executive in charge of product development and research, said Monday that the automaker had confidence in the reliability of its vehicle recorders.
“I've looked into this and there is no record of bad data from one of our EDRs,” Uchiyamada told reporters in Detroit.
But he said that the automaker had found a bug with the software used to extract data from the recorders.
The effect of the glitch was to make it seem as though some vehicles were traveling faster at the time of the crash than they actually had been, Uchiyamada said.
The automaker was asked by NHTSA about the bug in mid-June and reported that it had identified and fixed the problem.
In one case, a Toyota Tundra pickup truck went off a rural road in Washington state and killed the driver in 2007.
When Toyota examined the event data recorder, it showed that the vehicle had been traveling at over 170 miles per hour when the crash occurred, Toyota representatives said.
But that was far faster than the truck could have been traveling. The discrepancy was caused by the software bug on the reader used to retrieve data, Uchiyamada said.
The Tundra case was first reported by the Los Angeles Times in July.
As part of the reforms announced in response its recent safety crisis, Toyota made black box readers more widely available in the United States and has provided them to NHTSA investigators.
The 150 Toyota readers now available to investigate accidents in the United States are all now bug-free, company representatives said.
Most vehicles sold in the United States have EDRs although a safety guideline for their use and mandating that data from them be made available to the public does not take effect until 2012.
Uchiyamada said that the software problem with the EDRs had not contributed to the surge in complaints of unintended acceleration in Toyota vehicles that critics charge the automaker was slow in addressing.
“There is no relation,” Uchiyamada said.