I have an '09 Tribeca Limited and bought it used. Had 155,000 it. It has developed a vibration between 2nd and 3rd gears and 3rd and 4th gears. Dealer replaced the transmission and the torque converter before I received it. Went to the dealer to have the vibration checked out and when starting it to take the Service Manager for a ride to demonstrate the problem, the traction control light came on. The only code it shows is the P0068 for the MAP/MAF sensor and I can't figure why that would make the Traction Control light come on. Dealer thinks it may be rear drive shaft or rear differential. Any thoughts would be appreciated.