Problems with 2006 Nissan Quest VEHICLE SPEED CONTROL

While driving on highway the van started to shake while applying the brake and then there was no power as the gas was pressed. the gas was to the floor and the max speed was 50 mph. the more you drove the worst it got. i am only talking driving approximately 15-20 mile. when you first start out it is not as bad, but it is absolutely not safe to drive nor am i willing to drive it anymore. i have read articles on this and it certainly seems like a common problem. lets get it together nissan!!!!! i really want to know if going import is worth it. i have a 2001 gmc with over 175,000 with no problems. *tr

As you start off from a stop the transmission jerks in the lower gears, the speed surges then goes back down and there is an infrequent knocking noise. the transmission also starts to gear down as you go down a decline at speeds of 45-50 mph. *tr

On july 11,2011 i was traveling in my 2006 nissan quest minivan with my two children from my home in harwich, ma to my parent's home in ashford, ct. at about 1pm on a dry road, while traveling at about 65mph on ma route 25, my quest just completely shut down, no gas pedal response, no power steering, no power brakes etc. and the red check engine light went on. fortunately , the traffic was light and i was able to guide the quest to the side of the road, after a few minutes, i was able to re-start the quest and it then again ran normally. i scheduled an appointment for the july 12 with gates gmc nissan in windham, ct. the diagnosis of the problem (in their invoice c94977) was as follows: "c/s check eng light was on, check and report vehicle shut off while driving. did re-start and ran fine cause po643 sensor power supply found app sensorfault, no repair at this time, needs gas pedal assembly." gates did not have the electronic gas pedal which apparently caused this problem in stock and said it would take days to get one. i have been driving the quest since then without incident. clearly any major vehicle shut down at highway speeds as just occurred is a safety problem. i was fortunate that i could pull the vehicle over. if not, i could have been struck from behind. etc. obviously, something is wrong as shown by the incident above. i would appreciate whatever can be done to warn nissan and also to fix my vehicle. i have approx. 56,000 miles on the vehicle. *kb