cleanfreak

Hi Jim- Do you happen to know the TSB # for the exhaust replacement? I was told back in July of 2015 that the exhaust TSB would be released in October, that is October of 2015. Fast forward almost a year later with me checking every 2 months with the dealership to see if the Exhaust TSB has been released (to no avail) and this is the first mention of anyone actually having the work completed. Many thanks.

It was actually was a bad faulty cable that connected to the Display. They installed a new cable and I have not had any issues since.

My 2015 Yukon has been in the shop for over a week for the 'blank' screen issue. The first thing they did was the firmware update. All was said to be fixed and working. Two days later, when we went to pick up the vehicle up , the technician was driving the vehicle around to us and noticed the screen was blank again. The 2nd thing GM informs the tech to do is to check the connection between the HMI module and the screen. If the connections are good, then they are informed to order a new screen. The new screen arrived and was installed and we were told all is good and that they checked it twice with no issues. Today, they had the vehicle already pulled around waiting on me when I got there. Guess what? I get in the vehicle, start the vehicle......and still have a blank screen. The service manager sees me waving my hands in the air in frustration and comes to find it still not working. ........note, when pressing the screen, the stations will change, etc. but it is just blank....... I will assume the next step is to replace the HMI module itself, but from my research, it looks like those are not to stable either......... The service manager stated he was not for sure of the next step and we are awaiting direction from GM. I have truly come to regret purchasing this vehicle. Next month marks 1 year of ownership of this truck, with a total of 2 months of repair time in the shop.

I know this is an old thread, but this squeak just showed up in my 2015 Yukon SLT. It has 20K miles on it. Is it just the bushings?....or was it something major? It seems odd the bushings would squeak only after 20K miles.

For me, Yes. This has corrected my issue, or at least corrected it to where I can no longer hear or feel the vibration or buffeting...... However, My wife just text me and stated now there is a 'click' in the steering wheel when turning left or right. It does not do it while parked and turning the wheel.......It did not do this before the repair. I am now at my wits end....will the issues ever stop coming?!?!

***UPDATE*** The replacement flanged arrived on Tuesday, but was the incorrect flange for my vehicle. GM sent another one overnight and the dealer replaced on Wednesday. I received a call from my SM stating all was repaired and he gave me the new picoscope readings which were drastically better than the first readings. I was on my way on vacation when I received the call, so I did not get a chance to drive the vehicle until today. I am happy to report this flange replacement has fixed my vibration issue at 53 MPH and I do not hear any buffeting at 43 MPH. GM also will be giving me an extended warranty of misc items from 36K to 100K for my troubles. I have to say, I am happy with the result and with GM's offer. I will report back if the issues return, but for now, I am happy with the results. ....Now waiting for the V4-V8 exhaust fix to be released in October.......

***UPDATE*** My dealer has now had my vehicle another full week. As I stated in my previous post, my issue was supposed to be escalated to a specific engineer and that the next step was to get an entire new rear end housing. Needless to say, after a week, this did not happen. My Service Manager (SM) told me GM required him to do a multitude of test with a Pico scope (basically a device that measures vibrations). During the test they found the following results: The worst of the vibrations were at 53 MPH and the vibrations measured 29.7hz with a 49ng at that speed. The Pico scope also reported the vibration was coming from the driveshaft. They measured the driveshaft to the ‘nth’ degree and did not find anything unusual. Then they focused on the head end connection and the rear end connection of the driveshaft. They did several measurements and found the rear pinion flange to be warped. It was measuring .27mm at the top and .47mm when rotated (I am not 100% for sure what this means, but I assume it should be the same measurement). My SM stated the pinion flange looks to be cast incorrectly causing the flaw in the design. Basically, all of the testing took a full week and a new pinion flange was ordered on Friday and arrived yesterday afternoon. If everything goes as planned, including more test after the new pinion flange is installed, I should be able to test drive the vehicle this afternoon to see of this corrected my problem. I hope this solves both the vibration at 53 MPH and the buffeting at 43 MPH. I will report back at let you know my findings.

I do not. They should be able to look up the # in their system and print a 2-3 page document with pictures to show them how to repair. I saw the document, but I did not get a copy of it.

@jason-Thanks. You are correct, it is a mess and my patience is running thin........I still have a slimmer of hope...... ***UPDATE*** I have some information that might be useful to some. First, I found out (sort of) what the mysterious "muffler fix" is. It is actually a fix that is not available yet. When the vehicle changes from v8 mode to v4 mode there is a 'stutter' or short vibration during the transition. GM is well aware of this issue and they are working on a solution. The solution has to do with the muffler and the exhaust system. GM will be providing the new exhaust system in the estimated time frame of Sept-Oct. For what it is worth, my vehicle does have this ‘stutter’ transition issue, but it is not very bad. However, it is a major issue for the 2015 Tahoe I have for a rental vehicle. To me, it is funny how some vehicles experience various degrees of the same issue. ***Please note this has nothing to do with the buffeting issue, or vibration issue at 53 MPH*** I am not for sure if this has been made known or not, but a new Technical Bulletin (PIT5429) was released on June 1st to deal with “vibrations” or “Rough Harsh Ride” for Yukon Denali, Cadillac Escalade, and Tahoe LTZ, Suburban LTZ models built before 2/10/2015. These models have the Magnetic ride control Suspension (RPO Z95). My vehicle is not equipped with this, but it might be useful for someone. Please see attachment for the bulletin. PIT5429.pdf PIT5429.pdf PIT5429.pdf PIT5429.pdf

No. The rear end is not fixed. When they replaced the ring and pinion and set the backlash at .07", I believe the "buffeting" (sound only, no vibration associated with this sound) at 43MPH was gone. However, something was not set just right causing a new 'buffeting" sound that is directly associated with a new vibration that is most present at 53 MPH per my post above. In order for the dealer to be reimbursed by GM for the work they do on the vehicle, they must "go by the book". This 'book' is a laundry list of items to troubleshoot. The first item on the list is the headliner fix. Items on the list (in no particular order) are: Headliner TSB replace tires "muffler fix" Backlash testing a. Ring and Pinion b. New Chunk c. New Housing Since I assumed the tires and muffler fix was not the problem based on information I received from the Service Manager in Michigan, and provided proof (via the actual work order), they skipped the first few listed and went to the backlash testing. Speaking of which, I have a new update..... ***UPDATE*** I went to the dealership and test drove my vehicle on Friday. Due to the vibration at 53 MPH, they replaced the chunk in the rear end. They also repaired all of the rattles and figured out what the "liquid" substance was coming from the rear view mirror housing (there is a new bullentin out for this housing leak). After driving just 2 miles I quickly notice the vibration was still present and the replacement of the chunk did not resolve my issue. I drove the vehicle back and had a long conversation with my Service Manager. He stated they also reset the backlash at .04 after talking with a GM technical advisor. He showed me the documents that are produced stating what the backlash is/was to be set at and it showed .05 - .07. After talking with the GM technical advisor, the advisor stated this information needed to be updated and told him to set it at .04. Either way, the vibration was still there. He stated that since this did not solve my issue, the next step is to escalate the issue to a specfic engineer that will be in charge of my case and it will be given a case #. He stated the next step is to replace the housing altogether, which he is ordering today as long as the enigineer gives him the 'OK'. I now have a myriad of questions and thoughts going thru my head..... Did the vibration always exist, but was only noticeable when the changed the backlash setting? Is this truly what is causing the buffeting? Does this mysterious 'muffler' fix need to be done along with the other fix to be fully corrected? I will have another update as soon as I have something to report.

TSB # 3743752 will fix your issues as long as they do the all the work and install all the components per the bulletin. It is a simple fix once thay have all the parts in hand.

I am not 100% for sure. My Service Manager mentioned he would do the "muffler fix" next and the Service Manager from up North stated he had already done this fix and it did not correct the issue. When I told him this did not correct the issue according the SM up North, he started working on the rear end instead...... .......Now you got me wondering what it is as well

I honestly do not know. I will need to look to confirm. The headliner fix will not correct the buffeting issue whatsoever. There is a checklist of items that the GM Engineers require the dealer to go thru to try to solve the issue. The headliner is one of the first things on the list. To me, it was a waste of my time and the dealers money. The next thing on the list is the "muffler" fix.......

Hi Jason- Yes. I fully believe the 'buffeting' was gone with the new ring and pinion "backlash" repair at 42-43 MPH when I drove it home from the dealership (about 3 miles). The 42-43 MPH was the 'sweet' spot for my issue as well, so I was listening closely and drove this speed all the way home. My wife drives the vehicle more than I do and she told me that the buffeting had returned on Tuesday, 4 days after I picked it up. I was out of town during this time and not able to drive the vehicle until this Friday, when I was off for the 4th of July holiday. This is when I noticed it was a true 'vibration' causing the sound, not "just a sound", and this is what my wife was hearing. On a side note: The Service Manager from 1100 miles away called me this morning just to follow up and see how my repair went. Needless to say, this guy has gone way above and beyond for a vehicle his dealership did not sell, and he has never personally met me. Talk about customer service! I only wished he was here in South GA.......he now has a nice gift card in the mail During this call he told me to also be sure, and I quote verbatim, "if the tech found the hour glass wear pattern on the bearings, they should have replaced the axle housing to eliminate this problem coming back." ......Of course I asked this question to my dealership this morning via voice mail and text, still awaiting an answer.....

Thanks for your reply and the info. I will keep it in my back pocket and wait and see if this visit corrects my issue. The buffeting seemed to be fixed until this new issue came about. I did not check the carfax, but I did have them pull a service record on the vehicle on my last visit. My first visit a few weeks ago is all that showed up except for an oil change and when they did the required inspections to call it "certified".