A software update, available by the end of the month, will solve issues with the electronic stability control system on the 2010 Lexus GX 460 sport-utility vehicle, says Toyota Motor Sales.

Last week, Toyota had promptly halted sales of the GX 460 after Consumer Reports noted an unexpected handling behavior, and possibly a malfunction of the electronic stability control system.

The test behavior, in which the stability system allowed the back of the vehicle to slide out sideways when the driver lifted abruptly off the accelerator while going tightly around a corner (lift-off oversteer), could potentially result in a higher chance of rollover if the vehicle were tripped by a curb, dropoff, or change in surface.

Consumer Reports subsequently gave the 2010 Lexus GX 460 a rare "Don't Buy: Safety Risk" designation.

Toyota later confirmed that its own engineers had duplicated the behavior

Curiously, there's more to the story. Now Toyota Motor Corporation has also released a confession of sorts, explaining that several different conditions contributed to the issue:

- In the GX 460 and Land Cruiser Prado, heavy components, such as the fuel tank, are located on the left side, and in left-hand drive versions, the left side is made even heavier because of the presence of the driver.

- For vehicles with certain tires (on 18-inch wheels) and equipped with the Kinetic Dynamic Suspension System (KDSS*) and VSC, the activation of the VSC may not be sufficient in certain circumstances due to the setting of the VSC program.

- Circumstances may require advanced driving skills, such as sharp turns of the steering wheel in high-speed conditions or negotiating a curve to the right at excessive speeds.

It's an unusual (albeit indirect) admission—suggesting that Toyota didn't retest the vehicle's stability system for several key (U.S.-market) differences (like weight distribution, tires, or suspension) versus the closely related Toyota 4Runner and Toyota Land Cruiser Prado. But as for the third point—that advanced driving skills might be required for sharp turns—isn't stability control expected to help with those sorts of emergency maneuvers?

The recall now affects about 13,000 Lexus GX 460 models globally, including 9,400 in the U.S., plus about 21,000 units of the Toyota Land Cruiser Prado (a model not sold in the U.S.) that are left-hand-drive and equipped with both KDSS and VSC, and the fix will take about an hour.

U.S. owners will be notified in the mail starting in early May, but they can also contact Lexus Customer Satisfaction, at 800-255-3987; until a fix has been provided courtesy vehicles are on offer for those concerned about the issue.

And in the meantime, check out the video below, which helps show the differences between vehicles with the fix and those without.

[Toyota Motor Corporation]