More serious safety questions are now raised at Toyota's luxury division.

The Japan-based leadership of beleaguered Toyota Motor Sales late today gave an American sales executive permission to suspend sales of the new 2010 Lexus GX460 model. Another  safety recall or service action is now a distinct possibility.

The latest crisis at Toyota came after Consumer Reports issued a safety warning earlier.

Consumer Reports, a long time proponent – critics say cheerleader – of Toyota’s quality,  issued a rare “Don’t Buy: Safety Risk” recommendation. (See Consumers Union Defends Role in Missing Toyota Unintended Acceleration Problems and Deaths)

The last time Consumer Reports issued a “Don’t Buy” was for the 2001 Mitsubishi Montero Limited.

The Lexus GX460, the magazine claimed, was the worst, in terms of rollover potential among the 95 SUVs in its current automotive ratings.

The problem, apparently, concerns “trailing throttle oversteer,” or the tendency of the Lexus to have the rear end swing wide in a turn if the driver lifts off the accelerator pedal. This points the front of the SUV toward the inside of the turn. Uncorrected by either the driver or electronic controls, the SUV could hit the curb, creating a trip rollover.

As Consumer Report describes it, the electronic stability (yaw control) system of the Lexus does not intervene quickly enough, exactly the opposite calibration issue that Toyota engineering faced with the now  recalled regenerative braking system of the 2010 Prius. In that instance, the electronic controls were too aggressive in its application. Either way, Toyota’s ability to integrate electronics into its vehicles is once again called into question. And another safety recall or service action looms.

Consumer Reports said it validated its rollover warning by testing two Lexus GX460 models, with each repeating the problem, though neither rolled over. The magazine hedged, though, saying that it is not aware of any specific reports of GX rollovers in the real world.

“Lexus’ extensive vehicle testing provides a good indication of how our vehicles perform and we are confident that the GX meets our high safety standards,” said Mark Templin, Lexus Group Vice President and General Manager, who does not have any recall authority since it resides in Japan with Japanese executives who have been described as safety deaf by the U.S. Secretary of Transportation.

“Our engineering teams are vigorously testing the GX using Consumer Reports’ specific parameters to identify how we can make the GX’s performance even better,” Templin claimed.

Customer who have purchased a 2010 GX 460 will be given a loaner car until a “remedy is available.”

Both Toyota and the National Highway Traffic Safety Administration are facing heavy criticism for failing to act in Toyota and Lexus unintended acceleration problems, which allegedly have resulted in at least 52 deaths.

Before the stop sale was announced, Toyota released this statement: “We’re concerned with the results of Consumer Reports testing on the Lexus GX460 and their suggested buyer recommendation. Our engineers conduct similar tests and we feel these procedures provide a good indication of how our vehicles will perform in the real-world; however, we will try to duplicate the Consumer Reports’ test to determine if appropriate steps need to be taken. Please keep in mind that the 2010 GX460 meets or exceeds all federal government testing requirements.”

Toyota is also facing a $16.4 million fine from NHTSA for hiding information about safety defects – a mere pittance according to critics, who are lobbying for larger fines and even criminal charges.

The company also faces at least 200 lawsuits from accident victims or their estates, as well as shareholders concerning its handling of unintended acceleration and rollover incidents.