Steve.S

Hope not to bore anyone, but this a story of problems and frustration> Picked up my new 2020 GMC Sierra 2500HD Denali June 14 2020. (I leased it) My hope was to purchase it after this lease. I live in Texas but was in California for work and lease almost up on my 2017 Denali 1500 so started the move to the 2020 2500HD Denali, Dealership said I could get rid of old lease early and wit no penalties! NOT TRUE, as I found out later, still had to make last two payments! So I turned in 1500 and next thing I know I was told could not register it in Texas had to be done in California, Even if I had no California address or drivers License or California Insurance. After seeing all these roadblocks, I said to the Dealer, “give me my old truck back and I will go home in 30days and get it there!” Well next statement was NOPE, we can’t do that, you already turned it in! About two or three weeks Later, I found out from GMAC that was not true either. There were two more misstatements but oh well, make the best of it I figured! Anyway Now seeing frustration just ahead. After all this I talked to GMAC and to the California DMV, in which GMAC said I should make a complaint to BBB and also call GM to complain. The California DMV said there were no such rules as I was told, that the Dealer must have had some Internal rule. At 200 miles went in for problem, Infotainment screen was freezing and info center in the Dash was changing randomly. DIAGNOSSES, was nothing found and that I must be at fault. Hmmm we will watch and returned at 350 miles same complaint. Service writer said changing must be me, doing something wrong as they had not seen any problems with screen freezing, well tech wrote No codes give, NO problems found, 500 to 550 miles now seeing message come up said “In regeneration keep driving above 35 until finished” Drove truck on highway 30 miles at 60 to 80 MPH, did not go away. Back to dealer and was told they did software update and still did no see screen freeze or display problem but regen should be fixed. Some where around 700miles got message that in “65 miles vehicle would go into low power mode speed reduced” Dealer said DEF fluid low, filled it and off we go. Now I thought it was full when I got it but Dealer said probably not... Still wonder about that, but moving on Somewhere in this time frame I got that e-mail from General Motors asking how my experience has been. I answered it honestly about Dealer and problems and Misdirection or lack of being informed, or just a lie about the new lease??? Leave it that! Explained visits to service and felt better! Since I was now going to head back home called GMAC about lease and heading home. This is where and when I was told about Dealer was wrong about not giving my old lease back and could have gone home traded there! Also found out from California DMV that they should not have leased vehicle to as registered in California with Texas DL and Texas insurance. Jumping ahead, but about same problem and untrue information, I get a letter from California wanting California drivers license number and California Insurance! What a mess, and GMAC said they would help to get this fixed by sending papers to allow me register in Texas. This took 4 months to get done, and in the meantime, California was trying to twist my arm about getting California Drivers Licenses and about fines for not having it properly documented. GMAC sad I should write a letter to GM assistance about these misstatements and thought they may be able to help out. And guess what it did help, I got a call from GM Assistance and after explaining was told they had opened a case!!! Wow I am impressed and happy as I still like the truck and enjoyed driving it (Minus the small annoying hiccups) Now we are up to September or October of 2020. I started going back and forth with General Motors Assistance and of course I was told that all of this was an unusual case??? At tis point GM was looking at giving me assistance in recovering some of the expense I was out in Registration, the two payments I had to make but was told by dealer they would be forgiven plus extra money to register in Texas because CALIFORNIA or dealer marked it as commercial. Three or four weeks go by and was told the Claim GM STARTED WAS Denied! (Which I was ok with, not happy but OK) 48 hours later got call from same lady at GM customer service saying her manager had reversed the decision and wanted it t go up to a different department. It was denied again but two days latter got a call that said because of what I wrote about problems in the General Motors satisfaction report, and based on service reports of problems I was having that the claim was elevated to level 2 claim assistance center. The only difference now is I was told that it was being submitted for TRADE/BUYBACK under California lemon law! A week latter it was assigned to what is called Level 2 escalation team and a new rep would be contacting me. That did happen about 3 to 4 weeks later, and learned that what was now being waited on was a Trade/repurchase approval? For quite awhile was told it would be a trade. What was meant by that I was not sure of and in fact still confused over. In the meantime, at about 7,000 miles I had gone through 26 gallons of def fluid, GM replaced wiring harness, filter assembly and something else. Now not only freezing screens displays changing on their own, engine would crank for about 20 seconds and not start but wait 5 minutes and it starts in 2 to 4 cranks. Driving down road would just shut off, engine, whole dash and then just start running again. Twice it shut down I waited a minute and starts like nothing was at fault check engine light would come on and go off in a few miles, or by next day or two. Shop at one point said no codes given, and next time I go in, check engine light had been on and was off they said 11 codes thrown, several in history?? Infotainment still freezing and center info center still changing randomly. GM has special tech team look at and was told some of it is low voltage problem but no fix at this time. Drove in one time and system was froze, no touchscreen, nothing showing on info center. Service writer saw this condition and aid leave it he would tell them what he saw… When I picked it up latter and the ticket said could not duplicate condition, even though it was seen, according to Service manager, unless certified Tech sees problem nothing can be done. Different occasion went in and 10 codes found, check engine light on but told technician found nothing wrong with any of the systems error codes were connected to??? Now if I push brake pedal and hit start button, doesn’t start until I take foot off brake… This about half of what I have actually gone through in problems, In fact I have over 40 different error screens that have showed with check engine light coming on, and at times going off leaving no trail,,,, BUT Bored you are from reading? Well I will wrap it up. On 3/24/2021 received official GMC Customer Service Communication and from General Motors letter stating under California lemon law a repurchase / trade had been fully granted…. GREAT, Yippee, YAY, WOW. Well let’s not get excited as of 06/10/2021 we still don’t have a clue as to what is next. First was they contacted dealer I originally purchased from, BUT I was told they did not want to host a trade, repurchase. Found a different dealer and they were not excited about doing this trade? repurchase? General Motors is talking about but said they would. Later got a call from second dealer saying they did not want to… Found another dealer, this time in Texas and they said no problem we will take care of it just need to get some info from General Motors. Except no one is reaching out to anyone with direction. I was told to order one but dealer don’t have allocations, and supply is short. Downfall here is dealer has to wait to hear from GM and then order, and DEALER says they have sent emails, called and are not getting replies as to what next step is and I cannot order as I guess they are shut off now from Chip shortage? Plant closure? Or what? I was ready to order the day after it was approved, but dealer has to get answers, and I don’t blame them. They have seen my correspondence and know it is real, but Corporate is not responding I have a feeling I will have to order a 2022 the way things are going, which may not be bad if not many changes are happening. Even the dealer says he can’t get answers, in fact not even the dealers zone rep has been able to et an answer as to if, when, allotment problems etc.! So why do I write this? Simple I want others to see that a good thing may not be good! That even with all the problems I still have and live with and drive with, I am stuck with this Problem that someday may get fixed!!! Or replaced??? And when you think you got problems, think of what you read and add 50% more problems. I hope I did not bore you with all of this, but I am tired of the total run around. So just Think how lucky you are! Some say I am stupid, but I still want to stay with another GMC, and I have faith as I have always driven GM. Up until now the truck has been back to the shop a dozen times, all without them duplicating the problem. I have seen the 4 wheel light turn orange, felt shifting problems, seen a screen wanting system password, locked screens over a dozen times, engine just shut off while driving, no start several time, screen that said service transfer case, gone into limp mode twice, knocking noise just started, cameras just turn while driving down the road, seen about 20 or more codes the dealer has pulled from memory and close to 30 gal def fluid use at 10,600 miles. Had cruise control just shut off while driving, with funniest one being while driving down the road I would get the sensor go off saying vehicle next to me when there is nothing. Had cruise set at 65 when all of a sudden it goes to 75 or more with new cruise setting. Even had about a dozen cases where radio station would change or go from Sirus to phone or radio or media…. Maybe a ghost?? Today I was told if I order one 10 to 16 weeks for Delivery?? That is when they tell me how or when I can order. I think I am more tired of the lack of communication, not getting answers and not trusting what I am driving or not trusting the GM level 2 customer relations department who won’t return calls, or does not have an answer to any questions.. Well today is Jul 18th and the latest is 5 days ago I called customer service to ask what Is happening? They said they couldn’t believe it had gone on so long, and there had been such a lack of communications! I was starting to feel good and even got a call from the Level 2 GM representative who said he was sorry for not returning my calls, and he had them working on a solution! still don’t know who them was… and the promise he would call me back in one hour, five days ago, is still in the front of my brain. Customer service is not something GM has on their mind! Or they have just forgot what it means, what it should be! Through all of these months and days of fighting with my truck that sometimes runs and sometimes just dies and or farts like an old drunk on beans…….. Who knows maybe I can look at a 2022 that is loosing most of the good accessories! No HD radio for sure, some of the updates that were scheduled to be on the new model aren’t going to be there due to chips, or something!!! BUT I might get lucky and it would run without error codes being set or something freezing, or farting… better yet it wouldn’t drink 5 gal def in 90to 100 miles!

UPDATE; Well since dealer didn't want to do a "Reset" I went ahead and did it. removed battery cables, and just let it sit over night, Next morning took the Positive (+) and Negative (-) cables and put them together. (This draws in energy from the system and makes sure it is all flay. You can normally do this in a shorter period of time, but i got a lot of it! haha anyway I went in got coffee, did a little searching for new goodies or about 1 hour. Cleaned the ends and applied some good electrical grease and reconnected, crossed my fingers and turned the truck on. Checked the gauges and set them to a spot. (To see if they change again) Turned the truck off and let it sit for a few minutes. Pressed the Brake pedal and Hit the button. Truck turned over for about 7 seconds and no start. Hit the button and let sit for maybe five minutes while I rechecked everything I had done. Nothing was out of the norm so back in and pressed brake hit the button AND YEAH about 2 or three turns and crackled to life. let everything settle and just observed then went thru and did any missed setups, just like new! off on the test drive so trans could relearn and make sure all is well. #0 to 45 minutes of driving and all is well, so headed home. about 1 mile from the house and Check Engine light came on. #%^&&# truck, now what. pulled into house and thought take to dealer, but first wanted to see what code was thrown. Hooked up the tester and it said no codes, but yet I am staring at a orange light which I know means something should show. went in the house and stewed, then out to the dealer.. Truck started norm and light on I was headed off to dealer and want answers. back out of driveway put in drive and within a foot of moving Ck engine light off. Now as always if I go to the dealer and ask to check for codes they don't want to if light is not on. told them what i did and tech said he would check and if code was there they would write it up for what it shows. NO CODES, same as what i saw.... NOTHING.. A day of driving and all went good until next morning truck would turn over for 15 seconds and stop on its own no start... so i called and asked for tow truck, which they said would be about two hours.... an hour latter I thought i would try again as if it got there and started I would look like an idiot.. It started on second or third revolution so I am an idiot canceled tow and decided until it breaks all the way just live with it.... I do have a GM case going so called and explained what happened and was told they noted it and said if it does it again take it in.... Just wanted to update n the crazy thing

K&N has it, 5079 i think, 33-5079.... Going from memory so make sure. Same as 2019 except one corner cut off.... Go figure why, but it is for the working hood scoop and L5P...More will follow i am sure, everything going slow this year.... haha

I just sold my 2017 Denali 1500 6.2 and did a lot of searching, even tried 2 or three mufflers. Being old school i was looking for not to quiet, and not JUST loud... Found the Cherry Bomb and tried it. deeper sound, did not want Just loud, or obnoxious, just old school and the CherryBomb Vortex was it..... good sound, no drone. The Flowmaster was just loud and found out it did not flow as good as the Vortex, in fact some testing showed the Vortex flowed better than most of the mufflers and better than a glass-pack ... Two cents and an old ear is all I can give...

I have wondered the same thing, and did do a little research. The GM parts house shows a thermostatic valve, so it may be, most likely is, or very similar. I have not had the time to dig into front end to actually see it. Did make some calls and was told the replacement valve was the same? but that was after asking other workers if the valve was the same... so when i get the answer without the feeling it is a guess and not a positive fact i am going to investigate a bit more.... Besides if i take off the grill and get that far in I want to replace something!

I agree, with not finding proper fix on here. I was more curious to see if anyone else had similar problems so i don't think it is me although (I am pretty sure it is not). I have talked to GM about the random system problems. they are looking into solutions and ways to handle them. I like the truck, just upsets me that dealers will say "If it doesn't leave a code, and it is not something that shows up wen don't have a remedy. cars and trucks rely on to much computer control and computer diagnostics! I understand it's not the mechanic at fault as they have get an error code to just replace parts! which at times seems like a customer doesn't get the care they think they should. I do have a case with GM and it was mentioned that there is a chance they will do a buy back. which if it comes to that, i would take, but, during recent conversation with GM they asked if I had heard or seen this type of action with any other trucks or owners.... Having worked with GM on another truck, (8 speed trans problems) I know they don't just jump up and say lets swap vehicles. Thanks for the reply and i will stay on top of finding a solution.....

Sorry in advance for length, but several problems and have not shared everything about them!!!! ?? Am I crazy? are there ghosts? is any of it real? and it all leads to trust! I know new vehicles have a lot of electronics and they are harder to track down when it only happens occasionally. To me it is the most frustrating to go to the dealer and say this happened, I heard this, the truck did this! and they come back with "Mechanic checked it out thoroughly and everything is OK!" You drive off asking yourself did I really see this? did I do something? did I hit a switch I shouldn't have? The dealer tells you "If it is intermittent, unless we see it here, we cant fix it" And now my Problem, search for help, and seeing if anyone else has seen this? 1. 2020 GMC Sierra Denali 2500HD 6.6 Duramax Diesel. (Which driving off the lot I was so happy about) at about 200 miles I was diving around and noticed that the display in the cluster changed! I thought it was something I did and kind of ignored it. At 300 miles took it to the dealer, and explained the problem, got that look that says he doesn't want to look at it dummy! Later picked it up and was told I was problem, I must be doing it as mechanic says it is all good. and got told if it ain't doing it when you bring it in we wont find it unless it gives code! Left dealer but made sure display was at a known reference point. Later I saw it was at a different display again, so I did something you don't do often, got the manual out and read up on this. I leave the display on the economy setting just to see how It is doing and as a reference. Well it did do it and over time got worse! But not often enough to get the sound of "If it ain't doing it when you come in we won't find anything" I tried bumpy roads, hitting steering wheel, left turn, right turn, bump and turn, even took two boxes and taped over the switches on steering wheel. (Keeps the ghost out) anyway still changes, random and even saw it do it when shutting off, just as i pushed off button! Didn't repeat so dint take in.7,000 miles and dealer still says it must be me as Mechanic says no problems. But now read on as more ghosts appear! 2. DEF fluid, it is going someplace, that I know as I am feeding it to my truck and it keeps drinking. First incident was in Oklahoma, stopped, fueled up and filled DEF tank. Headed down the road and after Liver and cheese sandwich, singing to my self (about 100 - 120 miles) this thing called a Information display announced "DEF getting low" so I looked to see next fuel stop, and let the DEF display on, which said 4 green boxes above the empty (There are 8 boxes on display) My mind thought why and my analytical side said may go to a detail mode that shows more boxes before empty??? (Which I don't think it does) anyway 28 to 35 miles I watched one light after another go out as i pulled into the station. It took 6 gal to fill bought 3 of the blue Platinum, 2 full ones = 5 gal and about another gallon of the third. Now being a new to diesels guy thought this must be a "REGEN" ? which I have only seen displayed once since owning at around 400 to five hundred miles. I reading the manual again, and asking around i have been told that with only 8,000 miles on the truck, that my 17 to 19 gal of DEF fluid is high. (in history I had a check engine light and service message come on and stayed on two days then just went away, dealer I I stopped at said no codes, about 3,000 miles) Now in all this time I got a check engine light and service message again 7,000 miles, so took to dealer and in keeping truck for two days they couldn't find the reason but codes showed fuel heater! (BTW dealer said ck engine light was off next morning but showed codes, service light still on) ordered parts and to take it. (Four days of driving and service engine display stayed on the 4th day the service orange light came on. What happened next is combined with number 3 below.... Dealer replaced parts and i am again driving... I was told they have no explanation for DEF, and there is no gauge in DEF tank. ( So how does it know when getting low?) and why would that affect usage? 3. OK, what is next is mixed in with what you read above. On the road again with service message still on waiting for parts i went out to start truck and hit the switch, engine turning over and over and over, not starting and knowing something was wrong, hit the button again and kept cranking, seemed like at least 10 to 15 seconds and stopped on it's own. waited a few minutes and thought should i try again? I did and cranked for at least 5 to 8 seconds and started! whew, I took off and all seemed OK. stopped was in on business about 2 hours and came out and trucked cranked for again at least 5 seconds and started. good to go? well few miles latter stopped at Starbucks, came back out and engine started as normal! Put in reverse and camera came on, put in drive and took off. Few thousand feet and camera in back still on. I wanted navigation so I hit the home button, nothing, at 1/4 mile or more it switched at some point to front camera so i looked and found a turn in stop point at about 1 mile camera still to front and turned off truck. restarted and waited until all the screens settled. Put in reverse backed out and drive camera switched to front, driving again and seemed ok as camera went off about 1/4 to 1/3 mile navigation on.. I am good? Nope pulled up and in traffic and screen switched to front camera. I am watching traffic as i want to get off highway and check this out,when i noticed orange light in right mirror say vehicle there , but there wasn't any there in mirror glanced at left and orange light on, no cars either side so moved off road and as i stopped i saw center display changing screens like a deck of cards. Ok truck is now giving me the willies! took to dealer they put in parts and said no codes no problems, could not explain DEF usage said maybe part replaced. could not duplicate cranking so said no problem, said camera s OK not a problem so basically looked at me like I was an idiot and truck is OK. 4. Now i am at the point of TRUST, do you trust a life in a truck that does weird things? doesn't leave a trail, and makes you feel like no one believes you these problems happen? A. Cranking has occurred now three times in life of truck, last time it happened after parts replaced! B. center display has acted up since beginning, changing on its own, and the weird time it just kept changing. C. display not going off, locked on camera and or screen getting frozen on a certain display. once on cameras, once on apps, twice on phone screen. Finally was close to dealer and they got to see stuck screen and no touching or button combination would change it. (Waiting to hear form service manager) D. High DEF usage? or is it normal? since beginning. F. Center information Display going off twice with second time going off and back on after 15 to 30 miles, then off, but still random screen changes. G. last but not least is Trans temp. Something i don't normally look at if not towing. First time i saw was flat road and was changing screens it was at 260 i was at 75 and temp outside was at 85, i watched it drop to 170 after 30 miles and stayed that way for about 50 miles and stopped watching. Next time was at outside temp of about 70 75 degree, trans went fro 195 to 280 for about 10 miles and started dropping back to 165 then up to 195 then back to 165... don't watch it all the time but was told it was good and not outside of specs... My question why such a big fluctuation? and why change at all when not towing? So HELP,!!!! anyone else seeing odd things like this? How do you trust a vehicle that does this? Am I over reacting? is it a ghost? And my final question is what if something in the communications system, computer, was to go haywire? could it cause a situation that could cause an accident, loss of life and no one would ever know as the mechanic always says "Looks good, NO problems, NO codes" Sorry for length, but tried to keep it brief and still tell most of the story! every few weeks it seems like something new shows up!

Sorry in advance for length, but several problems and not all shared about them!!!! ?? Am I crazy? are there ghosts? is any of it real? and it all leads to trust! I know new vehicles have a lot of electronics and they are harder to track down when it only happens occasionally. To me it is the most frustrating to go to the dealer and say this happened, I heard this, the truck did this! and they come back with "Mechanic checked it out thoroughly and everything is OK!" You drive off asking yourself did I really see this? did I do something? did I hit a switch I shouldn't have? The dealer tells you "If it is intermittent, unless we see it here, we cant fix it" And now my Problem, search for help, and seeing if anyone else has seen this? 1. 2020 GMC Sierra Denali 2500HD 6.6 Duramax Diesel. (Which driving off the lot I was so happy about) at about 200 miles I was diving around and noticed that the display in the cluster changed! I thought it was something I did and kind of ignored it. At 300 miles took it to the dealer, and explained the problem, got that look that says he doesn't want to look at it dummy! Later picked it up and was told I was problem, I must be doing it as mechanic says it is all good. and got told if it ain't doing it when you bring it in we wont find it unless it gives code! Left dealer but made sure display was at a known reference point. Later I saw it was at a different display again, so I did something you don't do often, got the manual out and read up on this. I leave the display on the economy setting just to see how It is doing and as a reference. Well it did do it and over time got worse! But not often enough to get the sound of "If it ain't doing it when you come in we won't find anything" I tried bumpy roads, hitting steering wheel, left turn, right turn, bump and turn, even took two boxes and taped over the switches on steering wheel. (Keeps the ghost out) anyway still changes, random and even saw it do it when shutting off, just as i pushed off button! Didn't repeat so dint take in.7,000 miles and dealer still says it must be me as Mechanic says no problems. But now read on as more ghosts! 2. DEF fluid, it is going someplace, that I know as I am feeding it to my truck and it keeps drinking. First incident was in Oklahoma, stopped, fueled up and filled DEF tank. Headed down the road and after Liver and cheese sandwich, singing to my self (about 100 - 120 miles) this thing called a Information display announced "DEF getting low" so I looked to see next fuel stop, and let the DEF display on, which said 4 green boxes above the empty (There are 8 boxes on display) My mind thought why and my analytical side said may go to a detail mode that shows more boxes before empty??? (Which I don't think it does) anyway 28 to 35 miles I watched one light after another go out as i pulled into the station. It took 6 gal to fill bought 3 of the blue Platinum, 2 full ones = 5 gal and about another gallon of the third. Now being a new to diesels guy thought this must be a "REGEN" ? which I have only seen displayed once since owning at around 400 to five hundred miles. I reading the manual again, and asking around i have been told that with only 8,000 miles on the truck, that my 17 to 19 gal of DEF fluid is high. (in history I had a check engine light and service message come on and stayed on two days then just went away, dealer I I stopped at said no codes, about 3,000 miles) Now in all this time I got a check engine light and service message again 7,000 miles, so took to dealer and in keeping truck for two days they couldn't find the reason but codes showed fuel heater! (BTW dealer said ck engine light was off next morning but showed codes, service light still on) ordered parts and to take it. (Four days of driving and service engine display stayed on the 4th day the service orange light came on. What happened next is combined with number 3 below.... Dealer replaced parts and i am again driving... I was told they have no explanation for DEF, and there is no gauge in DEF tank. ( So how does it know when getting low?) and why would that affect usage? 3. OK, what is next is mixed in with what you read above. On the road again with service message still on waiting for parts i went out to start truck and hit the switch, engine turning over and over and over, not starting and knowing something was wrong, hit the button again and kept cranking, seemed like at least 10 to 15 seconds and stopped on it's own. waited a few minutes and thought should i try again? I did and cranked for at least 5 to 8 seconds and started! whew, I took off and all seemed OK. stopped was in on business about 2 hours and came out and trucked cranked for again at least 5 seconds and started. good to go? well few miles latter stopped at Starbucks, came back out and engine started as normal! Put in reverse and camera came on, put in drive and took off. Few thousand feet and camera in back still on. I wanted navigation so I hit the home button, nothing, at 1/4 mile or more it switched at some point to front camera so i looked and found a turn in stop point at about 1 mile camera still to front and turned off truck. restarted and waited until all the screens settled. Put in reverse backed out and drive camera switched to front, driving again and seemed ok as camera went off about 1/4 to 1/3 mile navigation on.. I am good? Nope pulled up and in traffic and screen switched to front camera. I am watching traffic as i want to get off highway and check this out,when i noticed orange light in right mirror say vehicle there , but there wasn't any there in mirror glanced at left and orange light on, no cars either side so moved off road and as i stopped i saw center display changing screens like a deck of cards. Ok truck is now giving me the willies! took to dealer they put in parts and said no codes no problems, could not explain DEF usage said maybe part replaced. could not duplicate cranking so said no problem, said camera s OK not a problem so basically looked at me like I was an idiot and truck is OK. 4. Now i am at the point of TRUST, do you trust a life in a truck that does weird things? doesn't leave a trail, and makes you feel like no one believes you these problems happen? A. Cranking has occurred now three times in life of truck, last time it happened after parts replaced! B. center display has acted up since beginning, changing on its own, and the weird time it just kept changing. C. display not going off, locked on camera and or screen getting frozen on a certain display. once on cameras, once on apps, twice on phone screen. Finally was close to dealer and they got to see stuck screen and no touching or button combination would change it. (Waiting to hear form service manager) D. High DEF usage? or is it normal? since beginning. F. Center information Display going off twice with second time going off and back on after 15 to 30 miles, then off, but still random screen changes. G. last but not least is Trans temp. Something i don't normally look at if not towing. First time i saw was flat road and was changing screens it was at 260 i was at 75 and temp outside was at 85, i watched it drop to 170 after 30 miles and stayed that way for about 50 miles and stopped watching. Next time was at outside temp of about 70 75 degree, trans went fro 195 to 280 for about 10 miles and started dropping back to 165 then up to 195 then back to 165... don't watch it all the time but was told it was good and not outside of specs... My question why such a big fluctuation? and why change at all when not towing? So HELP,!!!! anyone else seeing odd things like this? How do you trust a vehicle that does this? Am I over reacting? is it a ghost? And my final question is what if something in the communications system, computer, was to go haywire? could it cause a situation that could cause an accident, loss of life and no one would ever know as the mechanic always says "Looks good, NO problems, NO codes" Sorry for length, but tried to keep it brief and still tell most of the story!

I have the 2020- GMC 2500HD Denali Diesel and at 8,000 miles I have used a total of about 17 gal def fluid. Gauge I know is erratic, but think it may be related to info cluster problems I am having. Anyway at one point I stopped and fueled and topped off def. at about 100 miles warning came on saying DEF low. Over the next 28 miles (next fuel exit) I watched the indicator drop to the last mark. It took 6 gal to fill. Wow I thought it won’t make it home t this rate! Got in and drove 490 miles to next fuel stop and DEF only showed down one bar?/// I thought it was a fluke, so continued . When I stopped at a dealer I was told they don’t have a way of saying how far you can go on a DEF tank and it could vary, no check engine light, and was told they would not find anything unless code shown. So advised me to go on and watch it, or leave it and they would work it in some time that day or next morning! Ok is it me? Is it the truck? Or is it dealers that don’t know what to look for? So in 8,000 miles it has happened three times, I have gone through at least 17 gal or more of DEF, (I still have the empty bottles to show for it) I have only seen one “Regen cycle” and I am setting at dealer now while they look to see if there is problem... Which I am now told they see nothing wrong with truck, no codes, no problems found? Everything normal... Now I didn’t answer any questions, and I didn’t give any ideas,,, but I feel better about sharing and writing my frustration! Haha maybe someone will have an answer, but I am buying stock in DEF if I can, I might get my money back on used fluid.. adding this 11/19/2020. Dealership cannot explain usage, although they believe is high, said “there is no sender in the DEF tank, no communications method to say what level of DEF fluid is actually in tank” so how does the display know? And how can it be reliable? Am I dumping it on the road? Where is it going and why? it is hard to believe it does not have a level sensor!

I have the 2020 GMC Sierra 2500hd Denali and fell the same “more foot pressure needed to stop” feeling. Creeping forward at stop lights type of action... Just thought it was because of moving up to the 2500 and diesel! After 8,000 miles I thought I would get used to it, but still there! Maybe it is how the diesel brake system is? Don’t know if it vacuum assisted brakes or some other system but it does need a better feedback pedal feeling. The brakes do stop the truck, but more mass with bigger truck may need more caliper? More pressure to calipers? Or better tuning to foot pressure? It is something and although better at control now (me that is) is a conscious effort! It is a Body says foot is on brakes, and brain says you are creeping! Haha

From what i have been told and have played around with is the control arm of the magnaride sensor. take it off and it throws a code and rides rough. change the length without changing anything else and rough ride,. so what ever you change,you need to change the sensor arm/ height to put it back to it's original center sensor position. there are kits that were made to work with non magnaride systems, and now they put a level block in and ride is restored... the secret is the sensor position. The magnaride sense the acceleration and posistion of the shock and changes the shock response