Toyota recalling more than 1 million vehicles

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If at first you don't succeed, order a second recall. The RAV4 goes back into the shop.

Toyota's efforts to overcome concern about quality and safety could take a hit after word of its latest recalls.

On Monday, Toyota and the National Highway Transportation Safety Administration cited three separate voluntary recalls, involving a total of 1,015,259 vehicles built between 2006 and 2011. The recalls were only the latest in a long list by the Japanese auto giant.

The first recall is not only one of the year's larger safety-related recalls, but it also marks the second time the Japanese giant will attempt to fix a problem with the rear suspensions on 780,000 crossovers and hybrids that could lead to a crash.

Toyota found that a fix it put in place in August 2012 didn't solve the problem and will have to recall the vehicles again.

The two vehicles covered by the latest service action are the 2010 Lexus HS 250 hybrid and the 2006 through 2011 Toyota RAV4 crossover, the latter one of the maker's most popular models.

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The original problem involved a wobbling rear suspension arm that could, over time, rust out. That could lead to a suspension failure and, in a worst-case scenario, a crash. The maker has since discovered that the nuts it used to adjust the alignment of the rear wheels on the two vehicles during the August 2012 recall were not tightened properly.

The maker has notified the NHTSA it will now have to recall the same 780,000 vehicles to inspect for damage. The nuts will now be properly tightened and Toyota will take the additional step of sealing the rear lower suspension arms with an epoxy coating designed to prevent corrosion.

Toyota said it will have to stage the recall because of limited parts availability, with the entire recall process likely to be completed by mid-February. The inspection process actually began in June and Toyota told the NHTSA that the vast majority of those vehicles it looked at did not need further repairs. But it has no way of being sure which vehicles do need the fix without conducting the inspection.

In addition, Toyota, which seemed well on its way to re-establishing its peerless reputation for quality, also said it was recalling 133,091 hybrids from 2006-2010, including the Highlander and Lexus RX 400h models. Toyota said there was a potential for shutting down of the hybrid system, causing the vehicle to stall.

Transistors within the hybrid system's inverter assembly can experience heat damage due to variations in characteristics of the transistors built in parallel circuits. Should this occur, various warning lights on the instrument panel will illuminate, and in most cases the vehicle will enter "limp home mode."

In limited instances, the hybrid system will shut down, resulting in the vehicle stopping while it is being driven.

The Lexus RX 400h was previously covered by an unintended acceleration recall.

Toyota also is recalling 101,584 Lexus GS 350 and IS 350 models from 2006 to 2011 for loose bolts on the variable-valve timing system gear assembly, potentially causing the engine to stop while driving. The GS 350 was replaced with a new model last year and the IS 350 was replaced earlier this year.

Bolts used to secure the variable valve timing control device can loosen, causing the vehicle to stop while being driven. Early warning for this condition can be an abnormal noise just after start up.

Several makers have had to repeat recalls in recent months, including Honda which notified thousands of owners that a repair meant to prevent the short-circuiting of a master power window switch might not have been sufficient.

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Toyota Senior Vice President Bob Carter last week told reporters in Detroit that quality and safety are two of the maker's top priorities, adding that the company had redoubled its efforts in the wake of a series of problems involving so-called unintended acceleration that led to the recall of more than 10 million Toyota products worldwide.

Toyota was hit with a series of record fines for failing to respond to a known safety defect in a timely manner as required by law.

Compounding the issue, the maker has had more of its vehicles recalled than any other manufacturer operating in the U.S. during three of the last four years.

Despite such problems, Toyota's reputation has largely rebounded from its unintended acceleration problems, notes George Peterson, chief analyst with AutoPacific, though he cautions that continuing problems with quality and safety could again tarnish the maker's long-standing reputation.

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—By CNBC Contributor Paul A. Eisenstein. Follow him on Twitter @DetroitBureau or at thedetroitbureau.com. Joseph Szczesny contributed to this report.