Toyota faces a new source of potential trouble: Its efforts to fix recalled cars may not be working.
The problems still need to be verified, but complaints arriving at the US National Highway Traffic Safety Administration (NHTSA) suggest that cases of unintended acceleration are occurring even in cars that have had a recall-related fixup.
In complaints filed with the NHTSA, multiple owners of fixed Toyota vehicles have reported new problems with acceleration.
One owner of a 2009 Matrix said that on Feb. 26, about two weeks after a dealer had done recall work on her brakes and gas pedal, she tapped the brakes while going about 5 miles per hour in a parking area and "felt the car push forward."
"It's doing it again, Mom," the filer of the complaint describes her son saying. She said she put the car in neutral and then "heard the engine wind out like I had pushed the gas pedal to the floor." The driver was given a loaner car while the problem is sorted out, but she is not alone.
The possible problems may span a range of Toyota models.
The owner of a 2006 Toyota Avalon complained of unintended acceleration while backing up to park on Feb. 28. The car hit another vehicle, resulting in bumper damage. Recall work had been done 11 days earlier, to install a metal shim under the gas pedal, the complaint says. The driver put the car in neutral, and it "did not stop revving until it was turned off."
A 2008 Camry owner said her accelerator "stuck to the floor" causing the engine to rev while the car was on but unoccupied, on Feb. 14. Recall work had been done on the pedal and floor mat earlier in the month, the complaint said.
According to some news reports, more than 60 such complaints have been filed since acceleration-related recall work has been done.
Toyota said Thursday it is moving quickly to investigate the complaints.
"Although most of these reports have yet to be verified, Toyota has been and remains committed to investigating all reported incidents of sudden acceleration in its vehicles quickly," the firm said in a statement. "Toyota wants to hear directly from its customers about any problems they are experiencing with their vehicles."
Evaluations so far "have found no evidence of a failure of the vehicle electronic throttle control system, the recent recall remedies or the brake override feature," the company said.
Last month, Toyota said it would install a brake override system "on an expanded range of customers' vehicles." It said the system is not a core recall remedy, but is designed to "automatically reduce engine power when the brake pedal and the accelerator pedal are applied simultaneously under certain driving conditions."
In a letter to Toyota Friday, Reps. Henry Waxman (D) of California and Bart Stupak (D) of Michigan asked the company to clarify which models will get the brake override technology, and whether any new models will not have it. If some models that have electronic throttle control systems will not have the technology, the lawmakers asked, "please explain why Toyota cannot, or will not, provide this safety upgrade."
A lingering question is whether electronic systems are causing many of the safety complaints. In dealing with the recent recalls, Toyota's fixes have mainly focused on the potential for floor mats to slip and for gas pedals to become sticky.
The latest customer complaints emerged as Toyota held a rally designed to reinvigorate its workers and dealers on Friday. The firm is also pushing a round of customer incentives to boost new-car sales.