TOKYO - Long before the high-profile deaths, the lawsuits, the record recalls and the government reprimands, engineers at Toyota Motor Corp. began noticing red flags, reported Automotive News.

What they were on to eventually would explode into the company's worst-ever quality crisis.

It was March 2007, and engineers were getting strange reports about the pedals in Toyota Tundra pickups. Sometimes, the accelerator was slow to return to the idle position after being depressed.

They decided excess moisture caused swelling of the friction lever, a mechanism that controls the pedal's movement. Engineers changed the material and moved on.

In late 2008, more complaints came in -- this time from Europe.

Drivers of the Aygo and Yaris small cars, by then equipped with the new friction lever, said their pedals were sticking, too. Toyota lengthened the lever and changed material again.

In each case, Toyota wrote off the problem as a rare one-off or a driveability, not safety, glitch.

But that assessment changed last fall, when more cases popped up in the United States and Canada. It took from October 2009 to Jan. 21 -- nearly four months -- for the world's biggest automaker to pinpoint the same problem and recall 2.3 million possibly defective vehicles.

As chronicled in Toyota's Jan. 21 Defect Information Report to the National Highway Traffic Safety Administration, the buildup to the pedal recall was years in the making.

Safety experts say Toyota had ample opportunity to act sooner.

"They let this thing go way out of control and didn't deal with it early like they could have," Sean Kane, president of Safety Research & Strategies Inc., a consumer advocacy group and auto safety consultancy in Rehoboth, Mass., told Automotive News.

In many cases, it will be a jury deciding whether Toyota failed to act.

The company is besieged by lawsuits brought by people saying they were injured -- or had relatives killed -- in a runaway Toyota Motor vehicle. Key to the cases will be what Toyota knew and when.

One case was filed Jan. 22 by Los Angeles attorney Michael Kelly. He accuses Toyota of trotting out floor mat and pedal recalls to cover up deeper problems with its electronic throttle control system.

"First they said aftermarket carpets were causing the pedal to stick. Then they said it could occur with Toyota carpets. Now they're saying they want to change the gas pedal," Kelly told Automotive News. "The bottom line is when you step on the brake, it should stop."