First few months experienced truck lunging forward whilst attempting to stop. Expressed concern with service dept. They stated nature of the vehicle performance. March 2013 called GM service #[xxx] after experiencing on highway @ 65 mph the vehicle accelerating as I applied brake to slow down RPM's jumped to 4500 and accelerated. 3/21/13 mileage 24,565 was told by dealership no codes were found. Was referred by GM to tech specialist 3/26/13 @ 866 790 5700 ext. 32664 told to get second opinion then completely ignored by GM for follow ups. April 1st different dealership found code event stored in transmission control module from March 15th but no diagnostic was present, they cleaned the throttle body. Mid April 2013 brakes began pulsating on compression. Mid April frustrated and very concerned with safety called 800 lemon law found on line and kimmel & silverman advised GM / GM responded disclaiming issues. @ 28,429 miles 5/21/13 front rotors replaced and rear rotors resurfaced. Transmission dipstick tube fracture fix: Pipe insulation & zip tie. 8/20/13 brakes pulsating again & spongy - vibration noted by service but not addressed.brought to specialist; right rear rotor grooved & left rear had chatter marks. 8/29/13 went to amco they found 4 codes in truck on GM scanner which dealership denied there were any. Sept. 2013 received bulletin " throttle position sensor may cause engine to run rough ". getting no-where with GM or dealership and fearing for safety in Oct. 2013 I opted to trade the vehicle at a great loss as it was my only transportation. Mind you this was my 2nd Avalanche - the 1st one I'd had a front end accident; air bag never deployed, fortunately I was not injured and deemed the performance issues to be due to the accident and traded into this new Avalanche. I have documentation for all of this and have lost over $30,000 due to GM negligence. Information redacted pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6).

- Ashaway , RI, USA

I was in line at a drive through at burger king and as I pulled up to the cashiers window to pay for my food the engine started to accelerate. I put my foot on the brakes as hard as I could while the truck was shaking and lurching trying to go forward. I can't say for sure how high the tachometer was, but it seemed to almost peg for a few seconds while this was going on. Finally I jammed the transmission into neutral and the engine returned to normal idle. I say jammed because it took great strength to get it out of drive. For about 10-15 seconds this truck was totally out of my control. I drove away and parked for a few minutes to gather myself as I was visibly shaken..I was thankful that no one was in front of me in at burger king or that I was not in a parking lot somewhere where someone could have been injured or killed. I had brought this vehicle in more than once to the dealer (rk Chevrolet) and complained about the transmission not shifting properly and was always told they could not find a problem. After reporting this they decided to put a device to monitor the computer. I drove around with this for about 3 months and nothing happened and they said the data collected was inconclusive. Since the truck had just went out of warranty they said they could not do anymore. This is totally unacceptable.

- Virginia Beach, VA, USA

I own a 2011 Chevrolet Avalanche ltz and at times when the truck down shifts it will lunge forward. I really need to have my foot firmly pressed on the brake to keep the truck from possibly hitting something or someone in front of me. It does not do it all the time and it's rather random. I feel that is worse then it happening all the time because I don't know when to expect it. I have not received any notification of a recall, but I feel a fix is definitely in order. Something is not right and it could result in a crash.

- North Providence, RI, USA

I have began to notice when slowing down (foot off the gas and coasting with foot on brake, or brake applied) at any area where my speed decreases to less than 15 mph that my Avalanche will seem to sort of lunge forward. The first time I experienced this I believed it was related to me and ignored it. The next couple of times I experienced this I thought there may be something wrong with the gas or engine. I have spoken with several other owners (who own the same year model Avalanche and Suburban - the Suburban and Avalanche are made from the same frame/body/parts) and they state experiencing the same issue. I must be cautious to ride my brakes and be read to heavily apply them now when taking an off/on ramp and vehicles are in front of me as my vehicle has lunged forward before with vehicles in front of me. I noticed here that (at the time of this submission) that two other users have reported the same incident. I am hoping that my report here will help open an investigation with Chevrolet on this issue.

- Benton, AR, USA

The contact owns a 2011 Chevrolet Avalanche 1500. The contact stated when he applied the E brake, the vehicle suddenly accelerated without warning. The contact mentioned that he was able to maintain control of the vehicle by shifting into neutral and shutting off the ignition. The vehicle was taken to a local mechanic who was unable to diagnose the failure. The manufacturer was not made aware of the failure. The vehicle was not repaired. The failure and current mileage was 5,500. Updated 03/28/12 updated 03/29/12

- Freedom, PA, USA