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L9 works on the 2023 Silverado 1500 5.3 V8! I tested it today to and from work. Managed to get close to 22mpg with speeds up to 62mph. No vibration, no weird sounds, and no transmission weirdness!
Does it still work? I'm from Germany and I recently bought a 2022 Chevy Trailboss with the 5.3 l / 10 speed engine and I heard from the problems with the lifters. So I think about to buy the Pulsar LT to avoid this. I'm a bit concerned...
Thanks for the follow up on this after a year of changing your driving pattern and sharing your experience of using L9 around town for an extended period of time.
Great video. I bought a 22 Silverado, and it told to me that unlike the previous models, the newer engine didn’t just go from 8-4. The dealer told me that, with my 8 speed transmission, the deactivation could do any of 18 different modes, including dropping to only 2 cylinders. Now, I kept that truck about 18 moths, and found it to be very good at handling whatever was needed. After helping one friend with moving his belongings (including towing a car) from VA beach to Jax, we could tell when it was dropping down to 4 cylinders, due to my after market exhaust. What really truly impressed me though was driving from Tri Cities Tennessee out to Palm Springs to tow home a 1978 Thunderbird Diamond Jubilee edition. On straight runs, and running
How are you telling that the truck dropped down to 2 cylinders? I don't know of any indicator that says whether DFM is active, let alone how many cylinders it has dropped down to.
I did this also, as for mileage with my Silverado I've seen more variation depending if I had a headwind or not. My transmission temps down the hiway did increase to just over 200*, not really a good idea but not a deal breaker either. As for extending the life of the lifters it will. The lifter collapses when it unlatches and gets stuck in that position, if it never shifts it doesn't get stuck. Because of that I installed a AFM/DOD eliminator to check operation. It was 50 bucks, plugged into the ALDL port on my truck and works great. No more shifting cylinders, the trans runs over 15* cooler running down the hiway and it shifts much better with no lag waiting for a proper engine state to complete a shift. You can run around in manual mode but for the minimal cost the plug in mod it works very well for me and I don't have to think about anything except much better performance.
From what I've heard, once the lifter has "deactivated" and has been commanded to go back into use, is where the problem exists. They drop out and won't come back without some damage being done to the lifter, getting stuck and damaging the cam. my thought is that if you prevent the lifters from going relaxed in the first place, it lessens the chances of effing up.
Doesn't the problem exist when they are constantly having to work in different driving conditions?? Is it a "damned if you do and damned if you don't" scenario?
@@edscorsese It could be, but I think that if you're going to have something activating and deactivating hundreds or thousands of times a day that eventually it's going to fail. If you don't work the device, it's less likely to screw up.
I’m a mechanic by trade but been in the collision industry last few years. I can’t picture how they have lifters set to deactivate. Seems like it would be on a compression stroke maybe the exaust would stay open? I don’t get it. I’ll have to see some videos of it mechanically working I guess
Just watched this video. I have a pulsar LT, and I've been using it for over a year now with no negative effects . As far as shifting back in and out of manual mode to L9. That's just something I personally don't want to mess with. I like most of your mods and I'm in the process of doing several on them to my 2020 GMC 1500 Texas Addition. I'm not interested in doing a full exhaust I'm just doing a muffler, and looking for a good pair of quad tips that doesn't take the bank to buy. Keep up the good work. I really enjoy all your videos.
I used the system for over a year. Used a full tank of fuel over my normal driving week on average. Then started using L9 mode to prevent it activating. Started using only a half a tank of fuel during my normal driving week. Tested this by again using the system again a full tank a week. Went back to L9 moded again only a half a tank of fuel a week. I now only use L9 mode in my silverado. This is every day normal weekly driving. I haven't tested it for long distance freeway mileage. This is just my normal every day driving.
I had 2014 with afm. Bought Range AFM disabler. It kept my SILVERAYDO in V8. I read up on it before purchasing, and some said that they lost a couple of miles some said that they stayed the same and very few said they gained couple as I did. But in all everyone one was happy with the purchase. At the time it was $200. I’m sure it’s gone up a little but it’s something to look into. They do have one for DFM.
For the newer V8s with 10spd transmissions, the PulsarLT is the only plug-in option. It is $500+ depending on where you are and ordering it from. The install is a little more involved but still DIY
@@Donslife right on a buddy of mine bought a 2022 Sierra I was telling him about it so looked it up to verify if it worked for DFM ( it’s says it does on the range website ). Also looked for it on here and nothing for range DFM but pulsar LT. Thanks for the clarification, bud.
Great video very informative. I use this also in my 2012 Silverado. But I am taking it to a shop that will do a AFM disable through an HP tuner then I’ll be able to use six gear again, I believe my gas mileage will be almost as good as if it used AFM.
I've tried the L9 selection method for disabling the DFM in my 2023 Yukon XL and it appears to work as advertised. However, because my daily driving includes both town & country (highway) roads, I'm not sure how fast I should be driving before it becomes detrimental to the engine and should be switched back to the Drive mode. I'd like to purchase a Range Technology Plug & Play AFM/DFM Active Fuel Management Disabler; however, they don't yet make one for the 2023 GMC Yukon XL. 😕
I have 08 Silverado. Installed a A F M disabled. It has a 6 speed. 350k did pretty good. Changed oil religiously. Did pretty good...But it has worn out not only collapsed inner spring loaded but camshaft to. Very expensive repair. Love the truck. Other wise. Very dependable. 👍🏻 5.3 by the way
I have a 2020 with the 5.3 8-speed. Shifting to L7 does NOT disable the DFM on mine. It still dropped cylinders. Finally broke down and purchased the Pulsar LT. Well worth the money to no longer hear the choppy sound of the DFM. As an added bonus my exhaust has a spectacular sounding gurgle thru my flowmaster while slowing down with it disabled.
@@unscproductions5023I’ve had zero issues. It’s been installed now for 3 years. I really like the adjustable throttle. Not for hot rodding though. But for pulling our camper. Adjusting it to be more sensitive while towing keeps me from having to push the throttle as much. When normal driving I actually keep it turned to 10%negative to make it less sensitive.
I do a lot of travel in the mountains here in Oregon and oftentimes have to use the L gears when coming off the mountains behind slower traffic and not relying quite so much on the brakes. I didn’t realize I could switch to manual L7 (I have the 8 speed) while at a standstill. Thanks for that tip!
I have had 2 - 6.2's and my 2015 lifters failed, after replacement I immediately disabled AFM and never had another problem. My current truck is a 2020 AT4 and I disabled the AFM as soon as I got the truck, 45k no problems. I highly recommend deleting or disabling the AFM immediately, I would rather be safe than sorry. Engines were not made to run this way. I personally also have a catch can as well that I empty regularly between oil changes with lots of nasty goo inside that I would not want going back into the top of my engine. Cheers!
I just bought a 2024 Sierra 1500 elevation w/ dfm. Very helpful stuff. I love the truck but this is definitely something I’ll keep an eye on. I’ll prob drive on L9 to be safe, but also turn off the auto start/stop. Seems like this is the only worry with these trucks. Better than other defects with other trucks in my opinion. Anything else I could do to help prevent any dfm issues?
@@Donslife good to know. Thank you. I was driving in D today and i have an on/off button on my stop/start. Any time i drive in D I just turn that off too. Pretty smooth to be honest. I don’t feel any jump when i drive or lack of power. I’m gonna read the manual more when i get some time. Might start making videos about the truck also. Not many people on TH-cam that I see have these trucks.
Great Video Don! 2021 GMC Sierra 1500 AT4 with 6.2L with ~39k miles started sputtering with ticking and loss of power (has to be the lifter failure). I was able to limp into the shop. I personally change my oil religiously and the dealer is asking for all receipts to make sure there is no negligence to the motor. I have my own notes of when I changed the oil and some credit card statements showing where I purchased the oil (mobil 1) which I provided. I recently changed the oil 2 months ago and the dealer should be able to see that clean oil is in the system. Like you all, I am a GM guy, having ZL1, ZR1 and my AT4. Hopefully GM does not try to screw me over from a warranty claim. Any thoughts on how to defend my position of not neglecting my engine? Your thoughts are greatly appreciated.
Question is if you are changing these parameters around and then take the truck back for service work at the dealership will these codes show up ? Will the dealership try & void warranty based on changing those parameters ?
I have a 2013 Silverado Lt 5.3. I bought it used with 160k on it. At about 170k I had my first misfire on cylinder 7. I changed the plugs( #7 was burnt to a crisp). I didn't have any problems till about 190k and in one week I had 2 more misfires on cylinder #7 . At this point I did some research and found your video and applied your method to my every day driving and I'm at 200k and haven't had a misfire since. I get in put the trunk in Manuel and shift to 5th gear and pullout. no issues whatsoever. I also have done a muffler delete and still no issues to date.
"A bad lifter is a bad lifter. Even with DFM deactivated the lifter will eventually fail". I wanted a GMC Sierra Elevation but I can't buy one with the multiple quality issues of which the lifter issue is at the top. Only real option is a used Tundra prior to the change to the twin turbo mess.
My truck is a 2008 GMC Sierra 1500 5.3. My display is manual lettering no digital. I recently got the Engine code of P3400 Cylinder 1 deactivaton solenoid. I don't see a way to disable AFM.
I have been using this "manual mode" or L5 mode (6 speed transmissions) for several years now, on a 2016 Chevy 5.3L and on my 2018 Chevy 5.3L Silverado. It definitely stops the afm & stays running on all 8 cylinders. Several years ago, I asked my local GMC dealer service manager if A) does this really work and B) does it cause any problems or harm? He said yes it does work, and it causes no problems. I think I might be getting slightly less mpg but the difference is so little I don't notice it. As I am an old school guy, I think running it always in the 8 cylinder mode is easier on the engine.
Thanks Don for this very informative video. I was wondering about everything that you were telling us about. Specially the info on driving in L9 to avoid lifter failure. I just experienced this problem in the last month. I had to have all of the left bank lifters replaced on my 2020 GMC Sierra Elevation 5.3 liter because of lifter failure. I only have 12,500 miles on the truck so it was still under warranty and GM covered the cost. So when I found your first video on driving in L9 and how it might avoid lifter failure I was very happy. Now, after hearing what you said that it would not prevent lifter failure I not very happy😢. Thanks again for the information I do appreciate it. 👍
@@Donslife So, then, I'm going to assume you no longer suggest switching to L9? If it's accurate to say that it is only a matter of time before the lifters fail, then I'd rather run it in D and let the failure begin while my truck remains under warranty rather than delaying the inevitable and getting stuck with a repair bill after the expiration of warranty.
The products, such as the Range Disabler, help with lifter failure. In fact, my GM tech told me the lifters fail because they're not in use. Of course, that was an off-the-record comment, but I trust his opinion since he sees so many of these issues at the dealer.
AFM or DFM can activate in all modes except manual mode which is L9 in my case. It operates when the engine is below certain load thresholds. I am not the expert, but if you drive in towing mode, you’re just setting your transmission to hold the gears longer before shifting up. When you go down a hill or coast, AFM/DFM may start engaging until you put more load on the engine.
What aftermarket Device would you recommend to take care of auto stop and DFM? I know there is the pulsar device but dang 600 bucks is steep. Any other options? I would rather not go to L9
I have a 2016 5.3 with AFM. I have the range afm disabler and it works. The engine stays 100% on 8 cylinders. I don’t know if it’s going to prevent lifter failure but the truck drives much better.
Lifter failures at higher mileage is caused by waiting too long to change engine oil. 7k is waaaaaaay too long. 5k is pushing it, too much if there is a lot of short tripping in cold weather. Changing it by 4k is probably a good balance. Learn about the abrasive soot that direct injection makes and how that soot ends up in the oil. Learn about how full synthetic reacts when the engine is short tripped in cold weather.
I’d love be to know if my rumble on decel at 25-30mph is DFM, VVT, or torque converter. Does it M7 and M8. 2020 5.3 8-speed. So many systems cause similar problems.
What about driving in sport mode it kicks into lower gear? Does that help to disable activate fuel management. I feel that it runs better in sport mode.
I have a 23 Escalade and you have a DFM delete module for your truck but do you have one for Mrs. Donslife truck and if so were did you purchase it from
I don’t have a DFM disabler for either vehicle. We can shift to L9 and it works fine. As for which to buy, Pulsar LT is the most compatible with 6.2’s and the 10 speed transmission.
The number next to the L is the top gear you want the trans to go to. Like if you are towing something. You don’t want it to go into 10th because it’s an extra overdrive. Basically means that every time you touch the pedal, it will shift. Lowering the top gear while towing will lower your amount of gear hunting at higher speeds and keep you in a better power band.
Hey Don ---- Should I delete the AFM/DOD? I just purchased a 2012 Silverado 1500 5.3 with 120K miles -- It is a very clean truck that I believe was well maintained. Would you suggest I get a RANGE Technologies disable plug in OB2? Will the fact that these 5.3 with AFM have higher pressure oil pump cause issues and perhaps create excessive oil burning if the Disable device is used? Also would you recommend installing an OIL Catch Can along with a Range OB2 device?
I would consider doing both on a 2012, but ultimately it is your decision. I like that the AFM disable on the 2012 is less invasive and easily removed if needed compared to the PulsarLT option for mine.
I have a 2013 Avalanche Black Diamond 5.3 liter engine and I don’t have the mechanical experience to disable the AFM DoD fuel thing.. Should I trade in my mechanical fragile substandard Avalanche for a Kia? Nobody in Texas knows about it and refuses to help me fix my Avalanche..
What about the backpressure exhaust valve? I heard I can turn it counterclockwise and put a #8 bolt through it so it stays open. Will that hurt anything? Also about disabling the Dynamic Fuel Management system, can I have it tuned and disable that way?
L9 all the time, no shifting at all. The only time I shift back to Drive is if I am going to be on the highway for a road trip. Around the city, 100% L9
besides disable afm these silverados need a oil catch can. Otherwise engine carbons up and starts blowing out lifters and clogged piston rings. After 3000 miles mine has a full catch can of oil and sometimes moister. This would normally be circulated back into the engine where it burns up.
Man your aftermarket exhaust tone sound awesome. I feel it doesn't sound loud at low-mid RPM, am I correct? Please let me know the exact exhaust setup. Thanks
Thanks! Here is the video: BORLA S-Type Cat Back Dual Exhaust Install Review 2019 - 2023 GMC Sierra Chevy Silverado 6.2L th-cam.com/video/lzjipXNF1UM/w-d-xo.html
I just bought a brand new Tahoe 2024 with a 6.2 L engine and I saw your video and I was worried about it. I just got rid of a 2024 Duramax pick up truck diesel engine 2400 HD and believe me when I took it for inspection they said oh you need a software update at that point I said to myself all right I’m treating this piece of junk in and getting a Tahoe and now I found out about all this engine stuff so I did what you actually said I went to work one morning and there’s hardly anybody on the road so I did put it in L9 and you’re absolutely right it makes a world of difference, also when you’re sitting at a stoplight or a stop sign, the oil pressure doesn’t move as much so I know now that the solenoids aren’t firing. The oil is rocksolid now in L9. Thank you very much for the video very informative and you’re a professional when you make these videos really happy the truck runs really good and L9 now thank you again.
I have a 2024 Silverado 3500HD SRW with Duramax and had to get the emmisions software update with no difference is operation. The factory only downloaded part of the program and there was a recall on the emmisions. As a matter of fact, my check engine light did come on and I did the OnStar diagnostics check and they told me it was the emmisions. But as far as the 2024 Duramax being a piece of crap, it's one of the finest trucks I have owned. I had a 2021 Duramax before it and this one if significantly better.
I have found and plan to purchase a 2014 Silverado High Country with the 6.2L. Is manual mode available (L5 on the 6-speed) and, if so, is a separate AFM/DFM disabler necessary? Thanks.
What would be your recommendation for my 2014 GMC Sierra with a 5.3. Had to have 4 lifters and a bent push rod replaced in May 2023. I also pull a 6500lb travel trailer from time to time. Thanks
I am a big fan of full synthetic oil changes in 3000 mile intervals. I won’t claim that’s the big fix, but I have always done this. Especially if I was towing.
@Donslife I do the oil thing but a bit more than 3000mi. Maybe I will change that. GM recommends 7500 I think. But do two filter changes in that time. And last, I believe my transmission is a 6 speed. In the video I believe you say to use m5 around town but stay in drive on the highway and towing. Is that correct? Thanks for your time and help.
@@MyMoe9 personally if towing I keep it in Drive or Tow Haul mode, even while pulling in our out of the city at lower speeds. I think that AFM on a 2014 would stay in v8 mode almost always with a trailer at any speed. 99% of the time anyway. DFM can be all over the map with how many cylinders it chooses to engage.
I could try to explain it to you but if youre not a mechanic you wouldnt understand why deactivating dfm will absolutely prolong if not completely prevent lifter failure dfm lifters have 2 seperate oil passages its hard to explain but basically the part of the lifter that allows it intentionally to collapse to deactivate it by deactivating it you arent working that part of the lifter which means again you greatly reduce if not eliminate possible failure people really dont understand how they actually work and the best thing you can do if youre not going to do it the right way and do a full mechanical delete then you atleast need to get a tune that completely deactivates it
not sure if i missed the detail but does this only apply to certain years? im looking to pick up a 2007 yukon denali 6.2 in a few days, is this manual mode bypass going to be a thing for me ?
I believe it started with 2007-2013, 2014-2018) as AFM (4cyl mode) and DFM later. At least for the Sierra’s. You can use manual mode or purchase a inexpensive AFM disable device in your case
Hey Don! Thank you so much for representing the true north so well. I have a 2021 Sierra 1500 Elevation with the 5.3. I wish I was still blissfully ignorant to this issue but recent issues and codes are seeing my truck head to the dealer for service. I’ll find out tomorrow or early next week if this is my issue. I’m wondering though, since you did this about 9 months ago, are you still running around town in L9 and what has your longer term experience been? I’ve also been considering the Pulsar. If my problem isn’t actually lifters it may be beneficial for me to consider either of these options in the hopes of saving trouble later!
Hi Don I have exact same truck as yours year, Color, options. I hate the auto shut off/start, and DFM. Your videos have been most helpful. Cheers from Ontario
My 'M' mode on my tree says M3 and stays in like 3 speeds and winds out doesn't shift heading towards 50mph, I wont go any faster in 'M3' but my lifters are just starting to tick/tap some would say not bad at all, but I can hear it. 2013 Silverado 1500 5.3l ltz Would be nice to figure this out to squeeze more miles out of engine
@@JeffBarnaby-p8e See the problem with what you're saying is that in 99 the 5.3 didn't have all the extra AFM/DFM/DoD crap in it. So yes they were mechanically much more simple, reliable engines that are still on the road in vast numbers today having never been rebuilt. Once GM introduced the cylinder deactivation their reliability went through the floor because of variable state hydraulic lifters that can collapse and take the cam out causing you to need a serious rebuild that could get you to the $10k mark in repairs. Do you really want to buy a $40k truck that will likely need a $10k engine rebuild within 100k miles? I certainly don't. I recently sold my 2004 Silverado 1500 with the 4.8l V8 to a family member who was in bad need of a truck to work in. So when I buy another truck for myself (currently I can get around using either my primary or backup work van) I'm definitely not going to be buying a GM product specifically because of these engine issues. At this point I'd feel safer with a Ford with a 2.7l ecoboost than I would a GM engine with all the cylinder deactivation crap. I'll probably try to find a nice F150 with the 5.0 in it because at least it didn't have that crap (until either the 23 or 24 MY)
Hey Don, thank you for all of your videos! I have a 2024 5.3L 10 speed elevation with an aftermarket exhaust and typically drive it in L9 unless going above about 50-60 MPH. It seems to work great. I have read into if driving in L9 most of the time has any downsides apart from *maybe* fuel economy and came across it potentially being harder on the transmission. Is this something you've heard of and are you concerned about it?
Thanks for watching! In my opinion, the transmission is fine. I think towing is way harder on the transmission than using L9. I have not witnessed any real increases in transmission temps either. If anything, not using L9 I would experience some harder low gear shifts both up and down. Not often, but enough to notice.
My 2019 Gmc Sierra 1500 elevation has a 6 speed tranny but says on manual that L4 is the highest it goes and on 10 speed L7 the highest. Manual must be wrong cause I can get it too L6 would like too know the correct info on these trannys
Not guarantees, but these are some of my best practices: Made It This Far! My GMC Sierra AT4 Problems & Solutions th-cam.com/video/uV_RMUAikuc/w-d-xo.html
If it doesn’t go to past L8, then I would suspect you have an 8 speed transmission. L7 would turn DFM off. L8 would not disable DFM on an 8 speed transmission
@@Donslife my fault , I should have given more info. 2021 AT4 with 6.2L engine and 10 speed transmission. Seems odd that it is never above gear #7. I like the channel. a lot of good information here. Thanks
I just bought a 07 Silverado i didn't know anything about afm so when u found out i got sick to my stomach but come to find out the previous owner had did a complete afm delete he did the lifters push rods cam shaft also he got rid of vvt so i dont never got to worry about liter failing because it doesn't have arm lifters no more that god
Hey Don, question for you. In 2021 because of chip shortage, GM weren’t able to install afm/dfm on silverados/sierras after March (RPO YK9). Some say this is the “Unicorn” to search for and all your problems are solved. Others say the components are all still built in, just that the chip isn’t there to activate the system. So likely the crappy lifters will still fail. Was looking at a 2021 Silverado with RPO YK9 (no afm) locally and was excited, but now I’m not so sure. Any help is appreciated👍🏼
Lifters can't fail if they never unlock. As long as they stayed locked, which they will since the chip isn't there to unlock them, they aren't going to collapse. So no, the "crappy lifters" will not "still fail".
I was excited about this as well when I bought my 2022 . However, my truck still came with the dfm enabled along with the heated seats and steering wheel that it was supposed to retrofitted for. I just had lifter failure last week at 43k
The way cylinder deactivation works on a DOHC engine is totally different compared to a pushrod OHV engine. That isn't to say it will be reliable. Even Honda has had issues due to their use of cylinder deactivation.
Chevy 2007 5.3 with 94k miles has excess oil consumption (1 qt per 900miles) Some theory is AFM may be partial to blame,,, as well as the valve cover oil passages being the prominent issue. What are your thoughts on AFM in relation to oil consumption? TIA, Keith
@@Donslife gotcha. I have a 24 Ram with a Hemi and with the cylinder deactivation on, when coming to a stop it sounds like boulders rolling around in the bed. I know it’s the exhaust cause when that system is off, it significantly decreases that sound. Bottom line. I hate that stupid feature.
At 3:20 in this video I’m on the same page as you. Before my muffler delete mileage was up. Now with some good V8 noise mileage is down lol. Letting my 6.2L sing 🔊🔊
I have a 2018 Silverado 5.3 and an 8 speed transmission with a little over 58K miles. I drive in L7 almost all the time. I have notice at freeway speeds the rpm's are higher in L7 than in L8 or Drive. I would assume that means the fuel economy might be lower in L7. I don't check my mileage and the benefit of constant V8 power matters to me.
Have a question, how do you think exhaust will sound on a 2024 5.3 v8 with DFM ... muffler shop talked me out of installing one because of the Dfm will make it sound horrible, at this time they do not make a disabler for the 2024 10 speed for Chevy
It will sound fine in L9. Are you sure you don’t have an active exhaust on your 2024? It is a new feature they’ve added. I talk about it in one of my more recent videos
im no export but from my understanding, its the ware from the constant activating and deactivating on the lifter pins ,,, if its not doing that, it wont ware but what do i know lol
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Does your truck have the 6.2 L engine
@@SKANK_HUNT49 yes it does
@Donslife ty so just lock out 10th gear and it will fire on all 8 cylinders?
Will the gears still shift all the way through on L9?
L9 works on the 2023 Silverado 1500 5.3 V8! I tested it today to and from work. Managed to get close to 22mpg with speeds up to 62mph. No vibration, no weird sounds, and no transmission weirdness!
Thank you for the update! The viewers will appreciate it!
Facts
My 2021 Silverado was built during the chip shortage. It was built without DFM. I get 22 mpg. 5.3. True V8. No problems at all
How would one know if their 21 has the dfm chip or not?
@@Nectaris73 it was on my build sheet. I forget the exact code but it would be on it.
@@Nectaris73RPO YK9
😂
@@Nectaris73 There is a $50.00 deduct on the window sticker stating DFM delete.
I purchased a Pulsar LT a year ago, totally happy with the purchase. I wish GM would cancel the Autostop and DFM in their motors.
I did the same and I love it!
The auto stop in my 2020 trail boss has an on/off button.
Our government makes manufacturers reach high mileage requirements.
Does it still work? I'm from Germany and I recently bought a 2022 Chevy Trailboss with the 5.3 l / 10 speed engine and I heard from the problems with the lifters. So I think about to buy the Pulsar LT to avoid this. I'm a bit concerned...
@@insideoutsideupsidedown2218 my 2019 does too, but you have to push it every time you get in the truck. Pulsar disables it permanently
Thanks for the follow up on this after a year of changing your driving pattern and sharing your experience of using L9 around town for an extended period of time.
For sure!
Great video. I bought a 22 Silverado, and it told to me that unlike the previous models, the newer engine didn’t just go from 8-4. The dealer told me that, with my 8 speed transmission, the deactivation could do any of 18 different modes, including dropping to only 2 cylinders.
Now, I kept that truck about 18 moths, and found it to be very good at handling whatever was needed. After helping one friend with moving his belongings (including towing a car) from VA beach to Jax, we could tell when it was dropping down to 4 cylinders, due to my after market exhaust.
What really truly impressed me though was driving from Tri Cities Tennessee out to Palm Springs to tow home a 1978 Thunderbird Diamond Jubilee edition.
On straight runs, and running
How are you telling that the truck dropped down to 2 cylinders? I don't know of any indicator that says whether DFM is active, let alone how many cylinders it has dropped down to.
@@greghale717 I just did some research bc I could hear the different tones from the engine.
Plus the dealer had told me to be aware
Two cylinders? 😮 wow, learn something new everyday. That was a good read. Thanks for the info. Enjoy!
I did this also, as for mileage with my Silverado I've seen more variation depending if I had a headwind or not. My transmission temps down the hiway did increase to just over 200*, not really a good idea but not a deal breaker either. As for extending the life of the lifters it will. The lifter collapses when it unlatches and gets stuck in that position, if it never shifts it doesn't get stuck. Because of that I installed a AFM/DOD eliminator to check operation. It was 50 bucks, plugged into the ALDL port on my truck and works great. No more shifting cylinders, the trans runs over 15* cooler running down the hiway and it shifts much better with no lag waiting for a proper engine state to complete a shift. You can run around in manual mode but for the minimal cost the plug in mod it works very well for me and I don't have to think about anything except much better performance.
From what I've heard, once the lifter has "deactivated" and has been commanded to go back into use, is where the problem exists. They drop out and won't come back without some damage being done to the lifter, getting stuck and damaging the cam. my thought is that if you prevent the lifters from going relaxed in the first place, it lessens the chances of effing up.
Doesn't the problem exist when they are constantly having to work in different driving conditions?? Is it a "damned if you do and damned if you don't" scenario?
@@edscorsese It could be, but I think that if you're going to have something activating and deactivating hundreds or thousands of times a day that eventually it's going to fail. If you don't work the device, it's less likely to screw up.
I’m a mechanic by trade but been in the collision industry last few years. I can’t picture how they have lifters set to deactivate. Seems like it would be on a compression stroke maybe the exaust would stay open? I don’t get it. I’ll have to see some videos of it mechanically working I guess
@@sferg9582seems once it's deactivated it's permanent unless you remove the disabler.
Lifters are the failure.
Just watched this video. I have a pulsar LT, and I've been using it for over a year now with no negative effects . As far as shifting back in and out of manual mode to L9. That's just something I personally don't want to mess with.
I like most of your mods and I'm in the process of doing several on them to my 2020 GMC 1500 Texas Addition. I'm not interested in doing a full exhaust I'm just doing a muffler, and looking for a good pair of quad tips that doesn't take the bank to buy. Keep up the good work. I really enjoy all your videos.
I used the system for over a year. Used a full tank of fuel over my normal driving week on average. Then started using L9 mode to prevent it activating. Started using only a half a tank of fuel during my normal driving week. Tested this by again using the system again a full tank a week. Went back to L9 moded again only a half a tank of fuel a week. I now only use L9 mode in my silverado. This is every day normal weekly driving. I haven't tested it for long distance freeway mileage. This is just my normal every day driving.
I had 2014 with afm. Bought Range AFM disabler. It kept my SILVERAYDO in V8. I read up on it before purchasing, and some said that they lost a couple of miles some said that they stayed the same and very few said they gained couple as I did. But in all everyone one was happy with the purchase. At the time it was $200. I’m sure it’s gone up a little but it’s something to look into. They do have one for DFM.
For the newer V8s with 10spd transmissions, the PulsarLT is the only plug-in option. It is $500+ depending on where you are and ordering it from. The install is a little more involved but still DIY
@@Donslife right on a buddy of mine bought a 2022 Sierra I was telling him about it so looked it up to verify if it worked for DFM ( it’s says it does on the range website ). Also looked for it on here and nothing for range DFM but pulsar LT. Thanks for the clarification, bud.
Got the range in my 17’ 5.3 Silverado. Seeing 1 mile less mpg . Very minimal -
Bought one the other day on Amazon for $220
Great video very informative. I use this also in my 2012 Silverado. But I am taking it to a shop that will do a AFM disable through an HP tuner then I’ll be able to use six gear again, I believe my gas mileage will be almost as good as if it used AFM.
They do sell a full delect kit for this it replaces the cam, lifter pushrods.
Cool, who is offering it. I’d like to know more
I've tried the L9 selection method for disabling the DFM in my 2023 Yukon XL and it appears to work as advertised. However, because my daily driving includes both town & country (highway) roads, I'm not sure how fast I should be driving before it becomes detrimental to the engine and should be switched back to the Drive mode. I'd like to purchase a Range Technology Plug & Play AFM/DFM Active Fuel Management Disabler; however, they don't yet make one for the 2023 GMC Yukon XL. 😕
I have 08 Silverado. Installed a A F M disabled. It has a 6 speed. 350k did pretty good. Changed oil religiously. Did pretty good...But it has worn out not only collapsed inner spring loaded but camshaft to. Very expensive repair. Love the truck. Other wise. Very dependable. 👍🏻 5.3 by the way
Can’t complain too much with 350k
I have a 2020 with the 5.3 8-speed. Shifting to L7 does NOT disable the DFM on mine. It still dropped cylinders. Finally broke down and purchased the Pulsar LT. Well worth the money to no longer hear the choppy sound of the DFM. As an added bonus my exhaust has a spectacular sounding gurgle thru my flowmaster while slowing down with it disabled.
How has your experience with it been in thinking about getting one for mine but I’ve heard mixed reviews
@@unscproductions5023I’ve had zero issues. It’s been installed now for 3 years. I really like the adjustable throttle. Not for hot rodding though. But for pulling our camper. Adjusting it to be more sensitive while towing keeps me from having to push the throttle as much. When normal driving I actually keep it turned to 10%negative to make it less sensitive.
Don, I really enjoy your videos. They are very real life improvement and very informative. Keep them coming.
Thanks, will do!
Appreciate your videos Don! Always great clear info!
I do a lot of travel in the mountains here in Oregon and oftentimes have to use the L gears when coming off the mountains behind slower traffic and not relying quite so much on the brakes. I didn’t realize I could switch to manual L7 (I have the 8 speed) while at a standstill. Thanks for that tip!
Very helpful!!!! Coming from a tacoma to a new silverado I was not aware of this issue
Right on
I have had 2 - 6.2's and my 2015 lifters failed, after replacement I immediately disabled AFM and never had another problem. My current truck is a 2020 AT4 and I disabled the AFM as soon as I got the truck, 45k no problems. I highly recommend deleting or disabling the AFM immediately, I would rather be safe than sorry. Engines were not made to run this way. I personally also have a catch can as well that I empty regularly between oil changes with lots of nasty goo inside that I would not want going back into the top of my engine. Cheers!
I have the Pulsar, but I don't think it works for the refresh just yet.@rxw5520
Good to know. I just got a 5.3L V8 Elevation. Had no idea about these issues. Will buy a Range to put in to disable and keep it in V8 mode.
How big of an expense is lifter replacement on a 6.2L? Thanks.
Excellent video! Thanks! I’ll be looking for all your future videos!
I just bought a 2024 Sierra 1500 elevation w/ dfm. Very helpful stuff. I love the truck but this is definitely something I’ll keep an eye on. I’ll prob drive on L9 to be safe, but also turn off the auto start/stop. Seems like this is the only worry with these trucks. Better than other defects with other trucks in my opinion. Anything else I could do to help prevent any dfm issues?
When your transmission is in L9, auto stop/start is deactivated too. Some claim that more frequent oil changes can only help too.
@@Donslife good to know. Thank you. I was driving in D today and i have an on/off button on my stop/start. Any time i drive in D I just turn that off too. Pretty smooth to be honest. I don’t feel any jump when i drive or lack of power. I’m gonna read the manual more when i get some time. Might start making videos about the truck also. Not many people on TH-cam that I see have these trucks.
Great Video Don! 2021 GMC Sierra 1500 AT4 with 6.2L with ~39k miles started sputtering with ticking and loss of power (has to be the lifter failure). I was able to limp into the shop. I personally change my oil religiously and the dealer is asking for all receipts to make sure there is no negligence to the motor. I have my own notes of when I changed the oil and some credit card statements showing where I purchased the oil (mobil 1) which I provided. I recently changed the oil 2 months ago and the dealer should be able to see that clean oil is in the system. Like you all, I am a GM guy, having ZL1, ZR1 and my AT4. Hopefully GM does not try to screw me over from a warranty claim. Any thoughts on how to defend my position of not neglecting my engine? Your thoughts are greatly appreciated.
I think the burden of proof is on them if your records tell the story of regular maintenance
I don't have DFM and my lifters have gone twice in 1st 6000km. So I doubt disabling it matters at all.
Question is if you are changing these parameters around and then take the truck back for service work at the dealership will these codes show up ? Will the dealership try & void warranty based on changing those parameters ?
No you are using the powertrain in accordance with the owner’s manual. Nothing has been modified.
I have a 2013 Silverado Lt 5.3. I bought it used with 160k on it. At about 170k I had my first misfire on cylinder 7. I changed the plugs( #7 was burnt to a crisp). I didn't have any problems till about 190k and in one week I had 2 more misfires on cylinder #7 . At this point I did some research and found your video and applied your method to my every day driving and I'm at 200k and haven't had a misfire since. I get in put the trunk in Manuel and shift to 5th gear and pullout. no issues whatsoever. I also have done a muffler delete and still no issues to date.
Thanks for sharing
If it doesn't help lifter failure then why did the trucks without the V4 mode not have the issue with lifters and cams ? Or did they ??
The V8’s have had cases since 2007. Not all versions had V4 icons to display when AFM was active either.
"A bad lifter is a bad lifter. Even with DFM deactivated the lifter will eventually fail". I wanted a GMC Sierra Elevation but I can't buy one with the multiple quality issues of which the lifter issue is at the top. Only real option is a used Tundra prior to the change to the twin turbo mess.
My truck is a 2008 GMC Sierra 1500 5.3. My display is manual lettering no digital. I recently got the Engine code of P3400 Cylinder 1 deactivaton solenoid. I don't see a way to disable AFM.
I have been using this "manual mode" or L5 mode (6 speed transmissions) for several years now, on a 2016 Chevy 5.3L and on my 2018 Chevy 5.3L Silverado. It definitely stops the afm & stays running on all 8 cylinders. Several years ago, I asked my local GMC dealer service manager if A) does this really work and B) does it cause any problems or harm? He said yes it does work, and it causes no problems. I think I might be getting slightly less mpg but the difference is so little I don't notice it. As I am an old school guy, I think running it always in the 8 cylinder mode is easier on the engine.
Thanks Don for this very informative video. I was wondering about everything that you were telling us about. Specially the info on driving in L9 to avoid lifter failure. I just experienced this problem in the last month. I had to have all of the left bank lifters replaced on my 2020 GMC Sierra Elevation 5.3 liter because of lifter failure. I only have 12,500 miles on the truck so it was still under warranty and GM covered the cost. So when I found your first video on driving in L9 and how it might avoid lifter failure I was very happy. Now, after hearing what you said that it would not prevent lifter failure I not very happy😢. Thanks again for the information I do appreciate it. 👍
Ya it has been a learning experience for me too. Subpar components can fail anytime. Thank you for watching!
@@Donslife So, then, I'm going to assume you no longer suggest switching to L9?
If it's accurate to say that it is only a matter of time before the lifters fail, then I'd rather run it in D and let the failure begin while my truck remains under warranty rather than delaying the inevitable and getting stuck with a repair bill after the expiration of warranty.
The products, such as the Range Disabler, help with lifter failure. In fact, my GM tech told me the lifters fail because they're not in use. Of course, that was an off-the-record comment, but I trust his opinion since he sees so many of these issues at the dealer.
I just purchased a 2023 Silverado RST 5.3
I will see if this works in it and update you tomorrow!
Well?
@@trounbyfire it did work...
Does the afm activete in trailer mode? If not can we just drive in trailer mode ?
AFM or DFM can activate in all modes except manual mode which is L9 in my case. It operates when the engine is below certain load thresholds. I am not the expert, but if you drive in towing mode, you’re just setting your transmission to hold the gears longer before shifting up. When you go down a hill or coast, AFM/DFM may start engaging until you put more load on the engine.
@@Donslife Thank you
I’ve been running my 2019 5.3 in L5 for a year with no issues other than that annoying clicking stops. I always thought it was my transmission
so it stopped the clicking?
Is there a list of the factors that disable or enable DFM any where? Why is it s big secret?
What aftermarket Device would you recommend to take care of auto stop and DFM? I know there is the pulsar device but dang 600 bucks is steep. Any other options? I would rather not go to L9
You could try this: Auto Start Stop Eliminator / Bypass GMC Sierra AT4. Full Review and Installation!
th-cam.com/video/FGq25E2fRWU/w-d-xo.html
I am definitely going to try the L9 on my 2024 Chevrolet Silverado. Can you use the L9 when on the highway with speeds up to 70-75 mph?
You can but the rpms will stay a little higher. I shift to D personally at that point and DFM is certainly reactivating.
I sure hate that DFM@@Donslife
I have a 2016 5.3 with AFM. I have the range afm disabler and it works. The engine stays 100% on 8 cylinders. I don’t know if it’s going to prevent lifter failure but the truck drives much better.
I hear ya
Lifter failures at higher mileage is caused by waiting too long to change engine oil. 7k is waaaaaaay too long. 5k is pushing it, too much if there is a lot of short tripping in cold weather. Changing it by 4k is probably a good balance. Learn about the abrasive soot that direct injection makes and how that soot ends up in the oil. Learn about how full synthetic reacts when the engine is short tripped in cold weather.
I change every 3000 miles
is this truck a good daily driver I'm gonna be looking at a 2021 at4 6.2 used tomorrow
Mine is good for my needs and used for truck activities
I’d love be to know if my rumble on decel at 25-30mph is DFM, VVT, or torque converter. Does it M7 and M8. 2020 5.3 8-speed. So many systems cause similar problems.
Why can't gm get it together and make non failing lifters? Does the 2022 have this same lifter issues?
If lifter already failed and been driving for a bit too long should I replace enginev
A mechanic should be able to determine how much damage has been done
What about driving in sport mode it kicks into lower gear? Does that help to disable activate fuel management. I feel that it runs better in sport mode.
Unfortunately no, it will still engage, but likely just less cylinders will deactivate in sport
I have a 23 Escalade and you have a DFM delete module for your truck but do you have one for Mrs. Donslife truck and if so were did you purchase it from
I don’t have a DFM disabler for either vehicle. We can shift to L9 and it works fine. As for which to buy, Pulsar LT is the most compatible with 6.2’s and the 10 speed transmission.
The number next to the L is the top gear you want the trans to go to. Like if you are towing something. You don’t want it to go into 10th because it’s an extra overdrive. Basically means that every time you touch the pedal, it will shift. Lowering the top gear while towing will lower your amount of gear hunting at higher speeds and keep you in a better power band.
Always helpful!!!!!!!
Anytime!
Enjoyed your content very much and informative! What type of exhaust did you have installed if I may know?
Borla S-Type. Thanks for watching the videos!
I have a 2018 1500 5.3 had the DFM turned off by a tuner I know locally and it now gets 23 mpg while running all 8 cylinders.
How much charge?$$???
Hey Don ---- Should I delete the AFM/DOD? I just purchased a 2012 Silverado 1500 5.3 with 120K miles -- It is a very clean truck that I believe was well maintained. Would you suggest I get a RANGE Technologies disable plug in OB2? Will the fact that these 5.3 with AFM have higher pressure oil pump cause issues and perhaps create excessive oil burning if the Disable device is used? Also would you recommend installing an OIL Catch Can along with a Range OB2 device?
I would consider doing both on a 2012, but ultimately it is your decision. I like that the AFM disable on the 2012 is less invasive and easily removed if needed compared to the PulsarLT option for mine.
I have a 2013 Avalanche Black Diamond 5.3 liter engine and I don’t have the mechanical experience to disable the AFM DoD fuel thing.. Should I trade in my mechanical fragile substandard Avalanche for a Kia? Nobody in Texas knows about it and refuses to help me fix my Avalanche..
How do I turn off the DFM/AFM in my 2016 GMC Sierra 6 speed? I do not have "L" option on the shifter. Does anyone know?
Shift to M5
@@Donslife great! Thank you... Just tried it and the thing feels like I actually have a V-8 finally.
What about the backpressure exhaust valve? I heard I can turn it counterclockwise and put a #8 bolt through it so it stays open. Will that hurt anything? Also about disabling the Dynamic Fuel Management system, can I have it tuned and disable that way?
So do you just drive around in L9 regardless of speed, or do you shift through all the manual gears?
L9 all the time, no shifting at all. The only time I shift back to Drive is if I am going to be on the highway for a road trip. Around the city, 100% L9
besides disable afm these silverados need a oil catch can. Otherwise engine carbons up and starts blowing out lifters and clogged piston rings. After 3000 miles mine has a full catch can of oil and sometimes moister. This would normally be circulated back into the engine where it burns up.
I’ve been using one from UPR for a couple years now
Does a 2018 Chevy Express 2500 passenger 3D van with a 6.0 Ltr have AFM or DFM?
It might not have either. Most likely variable valve timing or VVT
Man your aftermarket exhaust tone sound awesome. I feel it doesn't sound loud at low-mid RPM, am I correct?
Please let me know the exact exhaust setup.
Thanks
Thanks! Here is the video: BORLA S-Type Cat Back Dual Exhaust Install Review 2019 - 2023 GMC Sierra Chevy Silverado 6.2L
th-cam.com/video/lzjipXNF1UM/w-d-xo.html
Here is a link to the exhaust:
amzn.to/42M6Jmm
I just bought a brand new Tahoe 2024 with a 6.2 L engine and I saw your video and I was worried about it. I just got rid of a 2024 Duramax pick up truck diesel engine 2400 HD and believe me when I took it for inspection they said oh you need a software update at that point I said to myself all right I’m treating this piece of junk in and getting a Tahoe and now I found out about all this engine stuff so I did what you actually said I went to work one morning and there’s hardly anybody on the road so I did put it in L9 and you’re absolutely right it makes a world of difference, also when you’re sitting at a stoplight or a stop sign, the oil pressure doesn’t move as much so I know now that the solenoids aren’t firing. The oil is rocksolid now in L9. Thank you very much for the video very informative and you’re a professional when you make these videos really happy the truck runs really good and L9 now thank you again.
You traded your Duramax HD truck that was a "piece of shit" because there was a software update?
I have a 2024 Silverado 3500HD SRW with Duramax and had to get the emmisions software update with no difference is operation. The factory only downloaded part of the program and there was a recall on the emmisions. As a matter of fact, my check engine light did come on and I did the OnStar diagnostics check and they told me it was the emmisions. But as far as the 2024 Duramax being a piece of crap, it's one of the finest trucks I have owned. I had a 2021 Duramax before it and this one if significantly better.
I have found and plan to purchase a 2014 Silverado High Country with the 6.2L. Is manual mode available (L5 on the 6-speed) and, if so, is a separate AFM/DFM disabler necessary? Thanks.
Manual mode will work in L5 to disable DFM. You do not need to purchase another device unless you want DFM disabled when in L6 or Drive.
Does this work on an 8-speed if you go to L7?
Yep. Exactly 👍
What would be your recommendation for my 2014 GMC Sierra with a 5.3. Had to have 4 lifters and a bent push rod replaced in May 2023. I also pull a 6500lb travel trailer from time to time. Thanks
I am a big fan of full synthetic oil changes in 3000 mile intervals. I won’t claim that’s the big fix, but I have always done this. Especially if I was towing.
@Donslife I do the oil thing but a bit more than 3000mi. Maybe I will change that. GM recommends 7500 I think. But do two filter changes in that time. And last, I believe my transmission is a 6 speed. In the video I believe you say to use m5 around town but stay in drive on the highway and towing. Is that correct? Thanks for your time and help.
@@MyMoe9 personally if towing I keep it in Drive or Tow Haul mode, even while pulling in our out of the city at lower speeds. I think that AFM on a 2014 would stay in v8 mode almost always with a trailer at any speed. 99% of the time anyway. DFM can be all over the map with how many cylinders it chooses to engage.
I could try to explain it to you but if youre not a mechanic you wouldnt understand why deactivating dfm will absolutely prolong if not completely prevent lifter failure dfm lifters have 2 seperate oil passages its hard to explain but basically the part of the lifter that allows it intentionally to collapse to deactivate it by deactivating it you arent working that part of the lifter which means again you greatly reduce if not eliminate possible failure people really dont understand how they actually work and the best thing you can do if youre not going to do it the right way and do a full mechanical delete then you atleast need to get a tune that completely deactivates it
not sure if i missed the detail but does this only apply to certain years? im looking to pick up a 2007 yukon denali 6.2 in a few days, is this manual mode bypass going to be a thing for me ?
I believe it started with 2007-2013, 2014-2018) as AFM (4cyl mode) and DFM later. At least for the Sierra’s.
You can use manual mode or purchase a inexpensive AFM disable device in your case
Hey Don! Thank you so much for representing the true north so well. I have a 2021 Sierra 1500 Elevation with the 5.3. I wish I was still blissfully ignorant to this issue but recent issues and codes are seeing my truck head to the dealer for service. I’ll find out tomorrow or early next week if this is my issue. I’m wondering though, since you did this about 9 months ago, are you still running around town in L9 and what has your longer term experience been? I’ve also been considering the Pulsar. If my problem isn’t actually lifters it may be beneficial for me to consider either of these options in the hopes of saving trouble later!
I used the Range Tech to disable my fuel management system on my 2015 until I did the dod delete.
If DFM is off in L9.... that would tax the lifters much less over time and in theory make them last longer no?
Hi Don I have exact same truck as yours year, Color, options. I hate the auto shut off/start, and DFM. Your videos have been most helpful. Cheers from Ontario
Happy to be of service
Very helpful. I wish they would just add a dfm on/off button
My 'M' mode on my tree says M3 and stays in like 3 speeds and winds out doesn't shift heading towards 50mph, I wont go any faster in 'M3' but my lifters are just starting to tick/tap some would say not bad at all, but I can hear it.
2013 Silverado 1500 5.3l ltz
Would be nice to figure this out to squeeze more miles out of engine
Waiting to get my truck back from GM now with bad lifters…. Can’t wait to get out of the 5.3 platform. Selling it as soon as it’s fixed
5.3is and has been one of best since like 1999’😮
@@JeffBarnaby-p8e See the problem with what you're saying is that in 99 the 5.3 didn't have all the extra AFM/DFM/DoD crap in it. So yes they were mechanically much more simple, reliable engines that are still on the road in vast numbers today having never been rebuilt. Once GM introduced the cylinder deactivation their reliability went through the floor because of variable state hydraulic lifters that can collapse and take the cam out causing you to need a serious rebuild that could get you to the $10k mark in repairs. Do you really want to buy a $40k truck that will likely need a $10k engine rebuild within 100k miles? I certainly don't. I recently sold my 2004 Silverado 1500 with the 4.8l V8 to a family member who was in bad need of a truck to work in. So when I buy another truck for myself (currently I can get around using either my primary or backup work van) I'm definitely not going to be buying a GM product specifically because of these engine issues. At this point I'd feel safer with a Ford with a 2.7l ecoboost than I would a GM engine with all the cylinder deactivation crap. I'll probably try to find a nice F150 with the 5.0 in it because at least it didn't have that crap (until either the 23 or 24 MY)
Bought a Diablo tuner just to disable AFM/DOD. My truck still gets 17-19 mpg all city running as a true V8.
They make tuners now for the 2020 and abover trucks? The ecm is locked now from GM.
Excellent info.
Thanks for Sharing.
My pleasure!
Hey Don, thank you for all of your videos! I have a 2024 5.3L 10 speed elevation with an aftermarket exhaust and typically drive it in L9 unless going above about 50-60 MPH. It seems to work great. I have read into if driving in L9 most of the time has any downsides apart from *maybe* fuel economy and came across it potentially being harder on the transmission. Is this something you've heard of and are you concerned about it?
Thanks for watching! In my opinion, the transmission is fine. I think towing is way harder on the transmission than using L9. I have not witnessed any real increases in transmission temps either. If anything, not using L9 I would experience some harder low gear shifts both up and down. Not often, but enough to notice.
@@Donslife Thank you for taking the time to provide a thoughtful response, the insights are very much so appreciated!
I have a 2015 GMC Yukon XL and towing my 7k pound camper it will still go back and forth between 4 and 8 if in Drive.
Maybe on deceleration or going down a slight change in grade
My 2019 Gmc Sierra 1500 elevation has a 6 speed tranny but says on manual that L4 is the highest it goes and on 10 speed L7 the highest. Manual must be wrong cause I can get it too L6 would like too know the correct info on these trannys
Is there any way to prevent lifter failed?
Not guarantees, but these are some of my best practices:
Made It This Far! My GMC Sierra AT4 Problems & Solutions
th-cam.com/video/uV_RMUAikuc/w-d-xo.html
I appreciate your videos.
If only I had known that L9 trick before I bought a pulsar LT
If your using the PulsarLT for other features it has, then it might be worth it
It's been common knowledge. Guys have been using manual move to disable it since at least 2014.
I have never seen my 2021 AT4 above L7. It doesnt matter what speed I am at, when I shift to "L" its in L7. Does this make sense?
If it doesn’t go to past L8, then I would suspect you have an 8 speed transmission. L7 would turn DFM off. L8 would not disable DFM on an 8 speed transmission
@@Donslife my fault , I should have given more info. 2021 AT4 with 6.2L engine and 10 speed transmission. Seems odd that it is never above gear #7. I like the channel. a lot of good information here. Thanks
There's a delete kit you can buy and install, also a performance tuner (diablo) for dropping the ecm programming. Never have to worry after that.!
The ecm is now locked on the newer GMC/Chevy motors.
@@hockeystop5 HP tuners will get you in, did my '18 when it had 12 miles on it. My boss just had his '23 1500 done loves it.
@@keithschnick5831 how do I go about having HP tuners unlocking my ECM?
I just bought a 07 Silverado i didn't know anything about afm so when u found out i got sick to my stomach but come to find out the previous owner had did a complete afm delete he did the lifters push rods cam shaft also he got rid of vvt so i dont never got to worry about liter failing because it doesn't have arm lifters no more that god
If I drive in sport or offroad will the dfm still work?
Yes unfortunately, DFM still works in all modes. Only manual mode as described in this video will disengage it without adding a device like a PulsarLT
My 10-speed 2024 Sierra 1500 only manually shifts up to "L8"...not L9. And in L8 it seems that DFM is still functioning.
awesome video thanks, maybe I'm hallucinating but it sounded as if you had an AWE exhaust, cheers!
Borla, but AWE is excellent too! Thanks for watching!
I disabled my 5.3 and it still collapsed a lifter at 97,000 miles along with lots of other issues. I'm done with Chevrolet.
Hey Don, question for you. In 2021 because of chip shortage, GM weren’t able to install afm/dfm on silverados/sierras after March (RPO YK9). Some say this is the “Unicorn” to search for and all your problems are solved. Others say the components are all still built in, just that the chip isn’t there to activate the system. So likely the crappy lifters will still fail. Was looking at a 2021 Silverado with RPO YK9 (no afm) locally and was excited, but now I’m not so sure. Any help is appreciated👍🏼
Lifters can't fail if they never unlock. As long as they stayed locked, which they will since the chip isn't there to unlock them, they aren't going to collapse. So no, the "crappy lifters" will not "still fail".
I was excited about this as well when I bought my 2022 . However, my truck still came with the dfm enabled along with the heated seats and steering wheel that it was supposed to retrofitted for. I just had lifter failure last week at 43k
Great review 👏 👌
Thanks 🙏🏻
I've read the '23 Chevrolet Colorado and GMC Canyon have this feature on their 2.7 litre engines, so I'll keep this in mind.
The way cylinder deactivation works on a DOHC engine is totally different compared to a pushrod OHV engine. That isn't to say it will be reliable. Even Honda has had issues due to their use of cylinder deactivation.
Have you found a dfm disabler compatible with your truck or just driving in L9?
I have been using L9 still. PulsarLT is still the only option I know off for plug and play
Chevy 2007 5.3 with 94k miles has excess oil consumption (1 qt per 900miles) Some theory is AFM may be partial to blame,,, as well as the valve cover oil passages being the prominent issue. What are your thoughts on AFM in relation to oil consumption? TIA, Keith
I tried this on my 2019 Sierra and it would only go as high as L8.
Then you need to shift to L7 (one gear lower than your transmission’s top gear, which is 8 in your case).
Will that work on a 2024 Chevrolet high Country with a 6.2L in all three driving modes?
Does doing this to disable dfm help oil consumption problem in these engines?
Good question, but since I haven’t had issues with excessive oil consumption, I can’t really say. Maybe someone else on this post can answer
Brother. What do you mean by “big surge” when coming to a stop when DFM is activated? Thank you.
There’s a small jump in RPMs as the truck downshifts and it sounds messy or undesirable
@@Donslife gotcha. I have a 24 Ram with a Hemi and with the cylinder deactivation on, when coming to a stop it sounds like boulders rolling around in the bed. I know it’s the exhaust cause when that system is off, it significantly decreases that sound. Bottom line. I hate that stupid feature.
At 3:20 in this video I’m on the same page as you. Before my muffler delete mileage was up. Now with some good V8 noise mileage is down lol. Letting my 6.2L sing 🔊🔊
Hows trans temp and I wonder if it adds extra wear on trans
I haven't noticed any changes in temperature or behavior of my transmission
I have a 2018 Silverado 5.3 and an 8 speed transmission with a little over 58K miles. I drive in L7 almost all the time. I have notice at freeway speeds the rpm's are higher in L7 than in L8 or Drive. I would assume that means the fuel economy might be lower in L7. I don't check my mileage and the benefit of constant V8 power matters to me.
I shift to Drive when doing highway speeds. L9 for me all around town which is most of my driving
Is the engine switching between 4 and 8 cylinder on the freeway? That is the only reason I drive in L7. Maybe I am wrong.
I’ve been running in L8 and it seems to make a difference. Maybe in my head but L8 down is all I have.
Try L7. L8 (if that’s your top gear) will likely engage DFM when the engine is under a low load and not working hard
Have a question, how do you think exhaust will sound on a 2024 5.3 v8 with DFM ... muffler shop talked me out of installing one because of the Dfm will make it sound horrible, at this time they do not make a disabler for the 2024 10 speed for Chevy
It will sound fine in L9. Are you sure you don’t have an active exhaust on your 2024? It is a new feature they’ve added. I talk about it in one of my more recent videos
@@Donslife , I believe I do, what will the difference be with active exhaust
@@Donslife can you send me link to that video
@@Donslife I do not have active exhaust
Here is that video:
Getting Personal! Answering Subscriber Questions! AT4 Mods, New Truck & More!
th-cam.com/video/Hl23jXP0rvM/w-d-xo.html
i have a 6 speed, my dash says v4 or v8 so i know what mode its in,,,, it works
im no export but from my understanding, its the ware from the constant activating and deactivating on the lifter pins ,,, if its not doing that, it wont ware
but what do i know lol
hola muy buen video gracia, tengo una 2022 Yukon 6.2 y me preocupaba ese tema del DFM, ya se que hacer gracias por compartir la información