Traction Control System Related Problems of the 2010 Lexus GX460

Traction Control System problem

I am writing to inform you of a potential significant safety defect in the 2010 GX 460 I recently purchased from Lexus of huntsville. I purchased the car new on the Friday the 7th of may. Over the weekend I found the car won't hold its place when stopped on an incline. In fact, the vehicle moves backwards unless I hold the brake down. I reported the problem to Lexus of huntsville on Monday the 10th and the car was taken in on Wednesday the 12th for a maintenance check. Lexus of huntsville reports this is normal for Lexus four wheel drive vehicles. I called the Lexus national helpline on 12 may to seek a second opinion as I have owned several four wheel drive vehicles and all have held their place on an incline. I was told I would be contacted by the Lexus GX subject matter expert shortly. On 24 may I called the national helpline a second time and was told after a thirty minute wait that the GX subject matter expert would call me back. As of today I have not heard back from Lexus and I am concerned and surprised by the lack of feedback on this potential significant safety defect in the 2010 GX 460.