2015 Yukon Denali

[benjamminharris]

Hello,
I just purchased a 2015 Yukon Denali with 101,000 on the clock. I used to sell GMC Yukon denalis from 06 to 08 so I know alot about those years. Can somebody answer my questions? I was reading that the 2015.5 had the 8 speed tranny, and wireless charger on the console. Does that mean mine was built earlier in the year, and is the six speed better? Also I don’t see where mine has AFM. It doesn’t have the ability to scroll from V8 to V4. I read about lifter problems in the 2015 Yukon, and Tahoes. Does anyone have an earlier built 15 Yukon Denali that would know the answers about the transmission, which one is better, and the AFM. I am new here so thanks for your time. Ben

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally assist you with your issue, but other members of this Forum much more knowledgeable than me in this area will chime in.

@NickTransmissions

 

[NickTransmissions]

Hello,
I just purchased a 2015 Yukon Denali with 101,000 on the clock. I used to sell GMC Yukon denalis from 06 to 08 so I know alot about those years. Can somebody answer my questions? I was reading that the 2015.5 had the 8 speed tranny, and wireless charger on the console. Does that mean mine was built earlier in the year, and is the six speed better? Also I don’t see where mine has AFM. It doesn’t have the ability to scroll from V8 to V4. I read about lifter problems in the 2015 Yukon, and Tahoes. Does anyone have an earlier built 15 Yukon Denali that would know the answers about the transmission, which one is better, and the AFM. I am new here so thanks for your time. Ben

Check your glovebox for the list of RPO codes applicable to your vehicle and then look up the codification for each online.

As far as which trans is better (6 vs 8 speed), to my knowledge there are no widespread lawsuits in progress against GM or suppliers for the 6L family of transmissions like there are with the 8Ls.

Quote my post or mention me (@NickTransmissions ) if you have additional transmission questions that you'd like me to answer...That said, if you do have the 6L80 and want to learn more about it, check out my '6L80 Info Thread' on here - you can find the link in my signature line.

 

[B-train]

Open the hood and look for a trans dipstick on the passenger side by the firewall. If there's a dipstick then you have the 6 speed most likely. The 8 speeds don't have one and the only vehicle I know of that came with one for an 8 speed was the camaro for a limited run.

As for the AFM, it has it - pretty sure anything after 2009 had it with the 6.2L and from 2007 on with the 5.3L. I think the only 6.2L that didn't get it in those years were camaro and corvette with manual transmissions.

Look through your menu screens on the dash and go to the INSTANT fuel economy screen. It should show up there and say either V8 or V4 while driving. Personally, I'd deactive that system ASAP with tuning or a RANGE Device.

 

[Thrust]

AFM may have been tuned out by previous owner. I have an early 2015 and it has AFM, or did till I had Blackbear tune it. It also has the 6-speed, no phone charger in the console or hands free liftgate.

 

[Seamus]

I owned a 2015 and 2017 Yukon Denali XL. The 2015 was horrible Dealer made good on a 2017 at cost to keep me as a customer. I had the 8 speed in both. I loved the 8 speed and it was great for towing and drivability. I had the 6 speed in my 2013 and hated it. Bogged down and always downshifting to be in power band. The 2015 does have AFM. The 2015 can be deleted and tuned. The 6 speed has been more reliable that the 8 speed is general cocensus.
The biggest problems with the 2015 were buffeting and booming, AC condensers, and horrible ride along with terrible seats. It does alot well but alot of growing pains in the 1st year.

 

[benjamminharris]

AFM may have been tuned out by previous owner. I have an early 2015 and it has AFM, or did till I had Blackbear tune it. It also has the 6-speed, no phone charger in the console or hands free liftgate.

This is what I was thinking. I’m surprised though because 2015 was the new body style for that generation and why in 2015.5 would they already make changes. Like transmission, and wireless charger. I do have power liftgate, and on key fob but I don’t think that it’s nessaerly hands free. When I scroll through there is no instant V4 or V8. I guess if the previous owner messed with it that’s prob better. I’ve never heard of GM making changes though halfway thru the year. Especially the first year of a new body style.

AFM may have been tuned out by previous owner. I have an early 2015 and it has AFM, or did till I had Blackbear tune it. It also has the 6-speed, no phone charger in the console or hands free liftgate.

 

[B-train]

This is what I was thinking. I’m surprised though because 2015 was the new body style for that generation and why in 2015.5 would they already make changes. Like transmission, and wireless charger. I do have power liftgate, and on key fob but I don’t think that it’s nessaerly hands free. When I scroll through there is no instant V4 or V8. I guess if the previous owner messed with it that’s prob better. I’ve never heard of GM making changes though halfway thru the year. Especially the first year of a new body style.

They are always making changes.....if my time in the engineering world is correct. Constant changes/problem solving keep many people employed. You can only product test so much and inevitably there are scenarios that creep in. Add that to parts suppliers trying to make margins, etc.

 

[the 18th letter]

This is what I was thinking. I’m surprised though because 2015 was the new body style for that generation and why in 2015.5 would they already make changes. Like transmission, and wireless charger. I do have power liftgate, and on key fob but I don’t think that it’s nessaerly hands free. When I scroll through there is no instant V4 or V8. I guess if the previous owner messed with it that’s prob better. I’ve never heard of GM making changes though halfway thru the year. Especially the first year of a new body style.

When looking through the DIC you will only see V4 illuminated if it’s activated. It should show at least the default V8 on the instant gas mileage screen.

 

[B-train]

You can choose which screens show up in the setup menu. Find fuel economy and select it as an active screen. Then when you go to the section that has driver stuff (forget the actual name) you should be able to scroll up or down ans find it along with oil life, tire pressure, mph, etc. Once you find it, take a cruise down a backroad and hit 55 mph and then roll back off the gas and see if the V8 turns to V4. If it doesn't, then maybe someone tuned it out.

 

[benjamminharris]

You can choose which screens show up in the setup menu. Find fuel economy and select it as an active screen. Then when you go to the section that has driver stuff (forget the actual name) you should be able to scroll up or down ans find it along with oil life, tire pressure, mph, etc. Once you find it, take a cruise down a backroad and hit 55 mph and then roll back off the gas and see if the V8 turns to V4. If it doesn't, then maybe someone tuned it out.

Cool. I will do that. Thanks you for the help. I am used to driving an 07 Tahoe for the last 10 years, so this thing is like a space ship to me .

 

[Thrust]

This is what I was thinking. I’m surprised though because 2015 was the new body style for that generation and why in 2015.5 would they already make changes. Like transmission, and wireless charger. I do have power liftgate, and on key fob but I don’t think that it’s nessaerly hands free. When I scroll through there is no instant V4 or V8. I guess if the previous owner messed with it that’s prob better. I’ve never heard of GM making changes though halfway thru the year. Especially the first year of a new body style.

You have to remember 2015s were being sold in April 2014. They probably didn't have everything ready at launch, or had supplier issues, therefore the mid year additions.

 

[benjamminharris]

True. I remember when I was selling GMC in 2007, and the 07 new body style hit the lot like March or April of 06. The 07 classic Sierra had a body style had half the year of 06, but 07.5 was newer body style. Then came the newer Duramax with exhaust filters, finally came Def, and now’s it’s almost 2024. Time flies.

 

[Tahoe14]

The start build date for the 2015.5 is October 15, 2014.

 

[gjbfromplymouth]

I own a 2015 Yukon Denali XL and have 99,000 miles. I mainly use it to tow a camper trailer. I had a lot of problems with shudder in the transmission until they replace the fluid with the newer and heavier LV ATF Mobil synthetic fluid. It takes about 20 quarts (over $400 with 2 hrs labor). I have had that done twice. I have the 8 speed transmission. At 80k front air ride shocks were replaced $2,100 and engine oil cooler lines and trans oiler cooler lines, both for $980. I have had door "applique moldings" replaced several times for over $300. Front brake pads and rotors replaced at 65,000 miles for $450. At 56,000 miles i had the valve lifters go out and it cost $3,250 to fix. That happened as I was towing the camper on a vacation. Three day delay in the trip. At 55,000 miles the AC condenser went out, but that only cost $475 to fix. At 45,000 miles $390 to change fluid in transmission per bulletin 18-NA-355.
I haven't added it all up, but I have spent more maintaining this vehicle than I have on all my other vehicles since I first started buying new vehicles in 1968. I like the vehicle but this is my last GMC vehicle ever. Nothing was covered by warranty except a battery in the second year. I have done all the required maintenance at GMC dealers.