The truck locks start locking and unlocking on their own, the stabilitrac and traction control will cycle between on and off, the motor will shut off, it goes to limp mode, check engine light comes on, traction control light comes on, abs light comes on, it has stalled in drive throughs on the interstate, driving around town, the vehicle is at pat clemons gmc in boone iowa, they replaced the bcm and it is still happening, there is an nhsta campaign #14V61400 for a chassis control module recall, this vehicle vin is not in that, but it does exhibit all the symptoms mentioned in the recall, very much a safety issue as it can happen anytime, especially when it is raining or snowing, started about a year ago

- Ames, IA, USA

I call this a "Panic breaking defect" I have experienced this on two different GMC vehicles manufactured 14 years apart. The first was a 1999 GMC suburban with mechanically operated throttle control. The second was my present GMC Yukon XL Denali with electronic throttle control. The defect: The close proximity of the accelerator pedal to the brake pedal makes it possible to have the right foot on both pedals at the same time. This results in high engine RPM and full breaking pressure, however, the anti-lock breaking system releases and re-applies the break pressure repeatedly allowing the vehicle to lunge forward a short distance on each cycle. To remove ones foot from the both pedals so as to apply it to just the break would result in the vehicle, engine being at high RPM, to allow the vehicle to speed forward resulting in a serious collision. True one could use the left foot, if able, on the break and then remove the right foot, allowing the engine to return to idle but on modern automatic transmission equipped cars where the left foot plays essentially no part in driving, such an action is not likely to occur. Also the ignition key could be turned off but with both hands employed to apply maximum pressure on the steering wheel to ensure maximum braking effort, that is not likely to occur either, besides that would result in lack of power steering and vacuum boost to the break system. A proposed solution: In a drive by wire environment it would be simple to send an idle signal to the throttle body every time the break pedal is pressed and this is the condition which occurs in a normal breaking situation. I have related this to the service manager of my local dealer and have also communicated it to General Motors Customer Support even offering to demonstrate the problem but have received no response. After all I am only a lowly customer and it matters not that I am also a retired Engineer!

- Sheboygan Falls, WI, USA

Monday 5th 2022, (2pm)I was driving with the AC on high as I had just left the mall. The interior was hot. As I left the mall and came to a stop light...the car would rev at stop, and continue to do so until the light changed. I had the oil and transmission fluid changed at 135000. It is currently at 138000. I turned off the AC because it did not seem to work (to cool the car down) and rolled the windows down and open the sun roof. Tuesday 6th, I was leaving the store (4pm) and again I turned the AC on and approached a stop light. When I stopped at the light, the car started revving or idling in pulses again as it did on Monday, however as I went to turn right onto the street, there was no power steering at all. Startled, I pressed the brake, shifted into park, turned the SUV off. Then restarted the SUV and the steering had returned to normal. I kept the AC off and drove home.

- Denver, CO, USA

The L94 engine P/N 19418446 with the variable lifters have a problem of failing and causing them to stick and damage the cam shaft. This causes a loud ticking in the engine and causes the engine to either be rebuilt or replaced at a cost of 5 to 8 thousand dollars with no consideration from GM. This seems to be happening a lot from talking to dealers and other mechanics. This is a know defect by GM as they no longer make this type of engine with the variabale lifters. If this is a known manufacturing defect GM should be responsible to correct the problem or be responsible for covering part of the cost to replace / rebuild the engine.

- Newark, OH, USA

The contact owns a 2013 GMC Yukon.the contact stated that while driving at an unknown rate of speed, a loud ticking noise occurred. The contact noticed a code was displayed on the instrument panel: P3400 cylinder deactivation system performance. The dealer nor manufacturer were made aware of the failure. The failure mileage was approximately 123,000.

- Charlotte, NC, USA

At 148000 miles going 35 mph cylinder 4 active fuel management lifter collapsed. I looked this up on the internet and this is subject of several technical service bulletins. This is a defect, this engine has received all regular maintenance and repairs at the dealership, never towed, and never off road with no modifications. This is about a $3000 repair just for the affected bank of lifters, $4200 to do both banks of lifters. This is unheard of in any other vehicle. GM knows this is a failure of this system and has done nothing but issue bulletins for its consumers.

- Hamburg, NY, USA

I was driving on the interstate about 70mph and the car started sputtering and traction control lights came on and I thought the car was going to stall and cause an accident. I was able to pull off on to the shoulder and look under the hood. I thought it was a bad sparkplug or something. I hooked up a obd reader and got code P0306. Got it towed to Firestone and they did diagnostics. They said it was a failed lifter, a known problem with GM vehicles. The ticking noise that it was making was from the failed lifter. I am hoping the camshaft is not damaged either.

- Derby, KS, USA

Was driving down the road going about 45 mph and vehicle felt like it lost power then it completely shut off. Had only gone about 3 miles when it happened. Was able to get to the shoulder and restart vehicle to drive back home. There were no warning lights or anything. It did seem like the engine was revving itself for a few seconds when I restarted it. Then it seemed normal and I was able to drive the approximate 3 miles back without any issues.

- Killen, AL, USA

Driver side exhaust manifold bolts have broken off at head.

- Edinburg, PA, USA