September 18, 2009

SANTEE, CALIFORNIA—A horrific sudden unintended acceleration crash that killed four – including a California Highway Patrol officer who was at the wheel of the 2009 Lexus when it plunged over an embankment and burst into flames – may raise the profile of SUA incidents as the National Highway Traffic Safety Administration weighs granting a defect petition to re-investigate the problem in Lexus vehicles.

On August 28, Mark Saylor and his wife Cleofe, both 45, their 13-year-old daughter, Mahala, and 38-year-old brother-in-law, Chris Lastrella, were killed after reporting to a 911 operator that they could not stop their Lexus ES 350, as it careened down Route 125. The tape of the brief call, released to the public last week, features the voice of Lastrella, telling the operator that the vehicle had no brakes. The call ended with occupants calling on each other to pray.

Despite reports that little was left of the burnt wreckage, among the components allegedly recovered from the crash were the brakes, the accelerator and the floors mats. CHP investigators have already speculated that a misplaced all-weather floor mat could have caused the crash, and Toyota is instructing dealers to inspect vehicles for proper floor mat installation.  Floor mat entrapment has been a convenient root cause for NHTSA and automakers in sudden unintended acceleration incidents, because ferreting out intermittent electronic problems is much more difficult and presumably more expensive to fix. Unsecured floor mats have often been suspected of or have taken the blame for sudden unintended acceleration. In the last 40 years, the agency has launched nine separate floor mat investigations; manufacturers have initiated 19 floor mat recalls.

In a press release issued on September 14, Toyota attempted to deflect rising concerns about electronic defects:

“We are instructing all of our Lexus and Toyota dealers to immediately inspect their new, used, and loaner fleet vehicles and we urge all other automakers, dealers, vehicle owners, and the independent service and car wash industries to assure that any floor mat, whether factory or aftermarket, is correct for the vehicle and properly installed and secured.”

Since 1999, NHTSA has received seven defect petitions to investigate sudden unintended acceleration, and launched eight SUA investigations into GM, Ford, Toyota and Volkswagen models. In the last decade, manufacturers have launched 31 recalls.

Many others who have studied the problem say that floor mat interference may account for only some of the reported incidents – the complaint data show that some vehicles and some manufacturers are outliers. NHTSA and manufacturers, however, tend to reduce that number by narrowly defining the problem and then throwing out complaints that don’t exactly fit.

The Lexus ES350 is a case in point. In October 2007, NHTSA closed an Engineering Analysis into unintended acceleration, affecting 55,000 2002- 2008 Lexus ES350 and Toyota Camry vehicles. Drivers had reported that vehicles continued travelling full throttle despite attempts to stop the vehicle. Some reacted by applying the brake pedal multiple times, depleting the braking system’s vacuum-based power assist and overheating the brakes, which further diminished the brakes’ effectiveness. Others attempted to turn the vehicle off by depressing the engine control button, unaware that the button had to be depressed for three seconds to stop the engine when the vehicle is in motion.

At the conclusion of an 11-month probe, Toyota and NHTSA’s Office of Defect Investigations concluded that the problem was floor mat interference. In September 2008, Toyota launched a recall to replace the all weather mats with a new design that, Toyota claimed, would reduce the potential for mat interference with the throttle pedal.

On April 8, the agency published the Opening Resume for another Defect Petition involving SUA and the Toyota Lexus. The petition was filed by a Lexus owner who had experienced an unwanted and uncontrolled acceleration event, but felt that the Preliminary Evaluation (PE7-016) was too narrow in scope and did not adequately address all complaints made to NHTSA about vehicle speed control concerns, according to the Opening Resume.

In the initial complaint to NHTSA, the driver described a “sudden uncontrollable surge in acceleration” causing the vehicle to accelerate from 60 mph to over 80 mph. The driver attempted to brake with both feet, but only reduced the vehicle speed to about 45 mph:

“With my speed reduced, I alternated between pumping the accelerator pedal and pulling up on it from the underside with my right foot as it became clear that the throttle was stuck in an open position. The vehicle continued to speed back up to over 65 mph with less pressure on the brake pedal.”

The driver finally slowed the vehicle to about 25 mph, amid clouds of smoke and the smell of overheated brakes. He shifted into neutral, and depressed the start/stop button, but nothing happened. Instead, the rpms began to increase on the tachometer. The petitioner described shifting back into drive.

“The vehicle jolted and rapidly accelerated to 60-plus mph. As the brakes were fading quickly, I was certain that I would need to shift back into neutral and let the engine blow up to stop the vehicle. Suddenly the acceleration surge stopped and I was able to bring the vehicle to a stop about 1 and a half to 2 miles from where it had started. I quickly shifted into ‘park’ and depressed the start/stop push button to turn off the engine. The vehicle seemed to shudder as I did so.”

The unidentified petitioner, from Plymouth, Minnesota, also requested an “investigation of MY 2002-2003 Lexus ES300 for those longer duration incidents involving uncontrollable acceleration where brake pedal application allegedly had no effect,” that were not within the scope of preliminary investigation. The agency has not yet decided whether to grant the request.

More on Sudden Unintended Acceleration:

Sudden Unintended Acceleration Redux: The Unresolved Issue (The Safety Record Vol. 6 Issue 3, June – July 2009)

Inspection Order by Toyota Linked to Santee Crash (San Diego Union Tribune, Sept. 15, 2009)