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About 14SLE

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  • Name
    Tom C
  • Location
    Southern Ohio
  • Drives
    2020 GMC Sierra SLT Crew Cab X-31

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  1. I have the same problem with the steering wheel controls on my '20 SLT and I'm glad someone else has confirmed it. The dealer, as usual, said they have never heard of this problem. At least 1-2 times on my 40 minute commute, I will press a "station advance" button on the steering wheel, the highlighted preset will advance on the radio, but the channel won't change properly. If you press the button again, it will change normally. Long-pressing the button seems to seek properly every time. In every regular (short) press of the button, there is a noticeable lag before the channel actually ch
  2. Personally, I am not sure how you tell what system your engine has unless you have the original paperwork. Your 2014 would definitely have been AFM (8 cylinder/4 cylinder). I'm not positive, but I believe I read that 2019's with the 6-speed transmission still have AFM. I believe my salesman said you could order either AFM or DFM with the higher trim levels. My dealership only ordered DFM on trucks when it was available. The DFM is definitely a major improvement--I just hope it holds up over the long term. GM has had some bad engine experiments over time (350 diesel, Quad 4, 3.4L head
  3. There are definitely times when I can tell DFM is active (rumble, vibration, etc.), particularly at low speeds. Fortunately, I have not started to hate it yet. The only options for full-sized trucks nowadays are: 1) Poor fuel economy (Toyota, Nissan), 2) Small engines with turbos (Ford), or 3) Messing around with variable displacement (GM, Ram). I have heard rumors that Toyota will be joining the turbo club on the upcoming Tundra (3.5L V6 with twin turbos). The use of adaptive ("learning") computer control can also cause issues because changing shift points and fuel delivery parameters can c
  4. My GMC REV cover was installed by the dealership right after I bought the truck. I noticed a fair amount of water in the bed after a decent rain or hand-washing the truck. I realized the seals were riding a bit above the bed rail and adjusted the clamps to make sure the seals were actually sitting on the plastic rails. That was a five minute adjustment and it helped a lot. I still get a bit of water in the back, especially if I go through a car wash to get rid of road salt--mostly at the rear corners. This cover is definitely not as dry as the GMC cover on my 2014, but I really like the h
  5. I have a 2020 GMC Sierra crew cab SLT with the 5.3L (DFM) and 10-speed transmission. Having previously owned a 2014 Sierra SLE with the 5.3L (AFM) and a 6-speed, there is no way I would ever buy an AFM/6-speed combination again. You can tune out the driveability problems, but doing so will void your warranty. I know you can put the factory tune back on the truck, but there is a firmware counter that keeps track of how many times the truck's programming has been updated. My dealer recommended getting a tune whenever I complained about the jerky drive train, but they warned me to wait until
  6. I have not yet seen any consumer devices that tell what DFM mode is currently active. There is a YouTube video showing a GM engineer riding along with the reviewer--the engineer is holding a device that displays a fraction indicating the current DFM mode. DFM is much more complicated than simply shutting down individual cylinder(s)--it has 17 firing patterns it can cycle through (16 reduced cylinder patterns plus full V8 mode). There is a unique firing pattern for each mode where a cylinder fires a fraction of the number of times that it would normally fire for the specific number of engine
  7. My '20 Sierra SLT has the occasional shudder at low speeds--I particularly notice it in a school zone on the way to work. It appears to be a resonance that occurs at a specific RPM and/or speed combination with DFM active. However, giving it a bit of gas pedal clears it up quickly, so I have to say it is WAAAYYYYYY better than the old nightmare that was AFM (lurch, chug, lurch, chug). You can probably eliminate the shudder with a Range Technology AFM/DFM disabler if you cannot live with it and don't want to risk your warranty. I had a Range unit for my old truck that is on its way in for a
  8. I'm not really fond of the radio coming on when the truck starts, but the folks at my dealership say that's the way the radio works. It is annoying, but I would much rather deal with that than the more serious issues I have had in the past. I just turn my volume down all the way instead of turning it off. I hope there is an update to fix this issue, but I'm not holding my breath from past experience. So far, my 10-speed transmission has been flawless. I'm very happy about that, because I did not enjoy the 6-speed clank-o-matic in my 2014 and I didn't even make it through a test
  9. I previously had a 2014 crew cab Z71 with AFM and the 6-speed transmission. The combination of the "learning" transmission and the AFM system resulted in some horrible driveline clunks and jerks that never got better as the truck aged. I loved the looks of the 2014-18 models, but I was pretty much done with AFM-equipped engines and started looking at other trucks last fall. I liked the way the Titan drove (very nice and totally clunk free), but their resale value is awful. Tundras are nice, but ancient and get horrific fuel economy (yes, I know it is a truck and I can afford the gas, but I don
  10. I had a 2014 GMC SLE Z71 crew cab pickup with the 5.3l (with AFM) and 6-speed. I had no problems with reliability, but there were a few annoyances with the overall drivetrain: 1) It seemed like the AFM became much more aggressive over time, even switching to 4-cylinder mode going up hills, etc. I ended up having to buy a Range Technologies box that I put on an OBD-II extension cable with a power switch to allow me to kill AFM during low speed limit stretches of road, otherwise it would continually switch between lugging (V4) and running smoothly (V8). 2) The 6-speed
  11. Since I still have over a year of time and mileage left on my extended warranty, I will wait and see how well the DFM and 10-speed transmissions hold up over time. My current truck didn't start acting like it is being manually shifted by a drunken monkey until about a year passed--I would like to see if that happens on the newer trucks before I drop a lot of money on a new one. Toyota is supposed to come out with redesigned trucks next year, so they may end up being more competitive. Besides, we may all be driving CyberTrucks within a few years...
  12. I agree that the 1 MPG difference caused by the Range device is totally insignificant. I have done the calculations and a Tundra would cost me about an extra $600 per year in gas. My wife and I pay cash for our vehicles, so that isn't likely to break us in the near future. However, as an engineer, I don't like using something woefully inefficient when other options are available without compromise. If I were really concerned about fuel economy, I would buy a Tesla Model X instead of a big pickup truck. That being said, my problem with the Tundra is the fact that is based upon 2
  13. Good advice. I test drove a Nissan Titan and loved it--it ran like a frightened deer and it drove really well. However, I have a friend who works for an automotive supplier and he recommended avoiding the Titan. He showed me pictures of a few parts on Internet automotive supply websites as examples and I can't fault his logic. Almost all of the Titan reviews I have read online (professional and owner reviews) have been mediocre at best. It's sad, because they are nice trucks. I have looked at Tundras, but they drive like an enormous vehicle (I'm 6'3", so it says a lo
  14. Thanks for the reply. I visited the dealership today and test drove two different SLT premium trucks with the 5.3 and 10-speed transmission. They drove very nicely. About a month ago, my salesman gave me a verbal trade-in estimate for my truck that was right in line with the KBB trade-in value, so I thought it would be worth investigating the cost delta to a new one. Of course, the dealership offered me much less than the verbal estimate today, so I am going to stick with my truck for the time being--it's pristine and still under warranty, so why not? I still have very serious
  15. I am getting close to the end of the extended warranty on my 14 SLE Z71 crew cab. The truck has not had any major problems, but I have not been a fan of the AFM system. Specifically, after about a year, the truck slowly started driving totally differently than it did when it was new. It went through the "clunk" and "slam" phase, then the AFM became more and more aggressive until it now tries to kick in all the time. I get really sick of the "lug", "lurch", "lug", "lurch" during the lower speed portion of my commute. The service department says the ECU has "learned" my driving situation and
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