Intermittent starting issue 2011 Yukon XL Denali [SOLVED]

[Dadnali68]

No security light flashing I assume not so I would look into the neutral safety switch
on the transmission and see if the inputs are correct. If it thinks it's in the wrong gear it won't start.

No security light. I have suspected NSS but haven't confirmed anything. Also still haven't had an issue since posting this. Y'all might be good luck lol.

 

[Dadnali68]

While I have all this great attention, I'd like to ask, are there some good threads to read about AFM/DOD delete, Z95 suspension repair or delete, and spare tire usage on the AWD models? My current engine is strong but it's starting to let exhaust manifold bolts go. I'd like to get a used motor and do the delete myself and drop it in once she get a little more clapped out. My front struts are bouncy and I'd like to replace them with Z71 style ranchos or bilsteins but not sure of the impacts on the Z95 megnerides. And my truck has stock 20s and the spare is an 18. Want to know if it's safe to use in an emergency with the AWD or if I'll blow the differential out with the size difference. Suggested reading material is appreciated!

 

[Dadnali68]

Also for those who have suggested I get a tech2. My dad gave me his Foxwell scanner. He used it like 10 years ago to diagnose a bad BCM on his 12 Sierra, so I'm hoping I have the necessary features to do what a tech2 would do. Will update as I use it.

 

[Geotrash]

While I have all this great attention, I'd like to ask, are there some good threads to read about AFM/DOD delete, Z95 suspension repair or delete, and spare tire usage on the AWD models? My current engine is strong but it's starting to let exhaust manifold bolts go. I'd like to get a used motor and do the delete myself and drop it in once she get a little more clapped out. My front struts are bouncy and I'd like to replace them with Z71 style ranchos or bilsteins but not sure of the impacts on the Z95 megnerides. And my truck has stock 20s and the spare is an 18. Want to know if it's safe to use in an emergency with the AWD or if I'll blow the differential out with the size difference. Suggested reading material is appreciated!

Keep the Z95 suspension. Replacement GM or Arnott rear air ride and front mag ride shocks are relatively inexpensive on rock auto (compared to dealer prices), as is the compressor if it needs it. We've seen folks go to regular shocks and regret it, going back to the factory mag ride/air ride setup. It's an incredibly effective and reliable system.

On the spare, if you run the calculations, it has the same diameter and circumference as the 20" wheels and tires, so it's safe to use in a pinch. I replaced my spare on my '07 with a new tire because the original was 16 years old at the time and I didn't trust it if I ever had to use it on a trip.

Exhaust manifold bolts are easy fixes when you come at them from the side after letting them soak with penetrating oil overnight. If you break any or can't get the stubs out, they sell a drilling and extraction template on Amazon that works great so you don't damage the cylinder heads.

Lots of threads on here with advice and learnings for AFM/DoD delete. I'm running a Cam Motion Stage 2 truck cam (3-bolt) in my 2012 XL Denali that I love.

Only other things I would recommend is 1/ only running premium fuel in that 6.2L, and 2/ replace the torque converter with a billet unit that has a stronger lockup clutch. And, 3/ Get that thing Blackbear tuned! Some of the best money I've spent. It will wake up the truck, make the transmission last longer, and they can tune out AFM, too.

 

[Dadnali68]

Well all, my luck ran out. Had to jockey cars around the driveway today. Fired it up remote start. No issue. Ran for 10 minutes, shut down for an hour. Tried to remote start, nothing. Got in, turned key, fired right up but had a CEL. Code P1682. Cleared the code, moved the truck shut it down. Realized I was off the driveway, couldn't see it due to snow! Went to fire it again and it cranked and cranked with no start. Tried again, long crank no start. Tried again, it fired but was lopey. Check engine light, reduced power warning, stabilitrac warning. Got the trucked moved and shut down and went in to watch Sunday night football. Y'all got any ideas what the hell my truck did?

 

[petethepug]

In the morning or tonight, disconnect and slow charge the battery. If DTC goes away you may have a battery that’s ready to let go.

Next step would be to slow charge overnight/ disconnected again and have it load tested at part shop.

Your truck has z55 autoride and is one of the best riding trucks they’ve ever made on those 20’s.

 

[Doubeleive]

Well all, my luck ran out. Had to jockey cars around the driveway today. Fired it up remote start. No issue. Ran for 10 minutes, shut down for an hour. Tried to remote start, nothing. Got in, turned key, fired right up but had a CEL. Code P1682. Cleared the code, moved the truck shut it down. Realized I was off the driveway, couldn't see it due to snow! Went to fire it again and it cranked and cranked with no start. Tried again, long crank no start. Tried again, it fired but was lopey. Check engine light, reduced power warning, stabilitrac warning. Got the trucked moved and shut down and went in to watch Sunday night football. Y'all got any ideas what the hell my truck did?

I would read thru this and see if anything rings a bell

https://www.justanswer.com/gmc/kvmjq-p1682-steps-solve-issue.html

 

[j91z28d1]

very general but sounds like ign power issues.

if it sets the code again. the freeze frame data could be helpful

 

[Dadnali68]

Well folks, get ready for this one. Went out today to look at the truck, Crack and no start twice. Fired third time but all warning lights on. Collected codes in pictures. Erased codes. All warning lights went away and idle returned to normal. Shut it down, started right up, no CEL, no warnings. I'm tossed. Mechanic thinks bad battery. I think it's something more but I will start using a battery tender on it since it sits a lot between drives. I should also mention sometimes volts are below 14 and sometimes they are above 14.

 

[Doubeleive]

the hvac codes are likely unrelated but there is a TSB out there for the transmission harness having some of the pins not inserted properly and it causes a whole host of issue's, might be a rabbit hole but not hard to check out also.
some of those codes and your issue's match the known problems reported in the tsb

https://static.nhtsa.gov/odi/tsbs/2012/SB-10043829-6448.pdf

 

[petethepug]

Since I last posted I had a breakthrough in our 09 Esky. It had intermittent long, slow crank, sometimes no start, sometimes studder accelerating out of corners. All intermittent, no related CEL.

It finally revealed itself as the crank position sensor P0355 and only gives a code randomly and simultaneously with the tacho not working.

If your exhaust manifolds are leaking plan on purchasing a set of OEM motor mounts, exh mani gaskets and ARP stud kit for the manifolds.

ARP do not snap, motor mounts are a breeze with exh mani out and you’ll be way ahead on price & longevity going OEM parts for another decade.

Deleting the z55 will make you want to get rid of truck. GM made z55 replacement struts guaranteed for life. They’re one & done now. Here’s the parts list from R/A to rebuild the front z55 on your Denali. Disregard the TPMS & z95 Magneride (Esky) struts and order z55 / autoride.

 

[Dadnali68]

Lots of good material here. Haven't had the issue in a few weeks. I'm wondering if it's a bad ground somewhere. I sprayed the whole underside with Fluid Film Black (got the $100 woolwax gun off amazon and a gallon of FF, I highly recommend this process for trucks that see salt like we get in NY.) And since then no issues. Maybe it's insulating a bad ground from water? Maybe it's low voltage and me driving it and keeping it on a tender when not driving is helping? Maybe I'm lucky? Either way. Also keeping the suspension stock. Found Arnott full strut assembly on summit racing for a reasonable price. I'll be doing them in spring once the snow and salt are gone. No sense rusting new parts!

 

[Dadnali68]

Updates. Truck went full no start. Would crank and crank but not start. Had it towed to a shop. They diagnosed bad relay to the PCM. Going to pick it up tomorrow. Side note, driver side heated seat stopped working. They found a burned wire in the pigtail under the passenger seat and 3 ohm resistance in the lower heat element and 13 ohm resistance in the upper heat element. Had them do the pigtail, sounds like I might need to do an upper heat element in the seat. Oh also they quoted me 2k to do upper and lower ball joins. So in the spring I'll be doing upper and lower control arms, struts, and sway bar links. All that will come out to less thank 2k and it'll be a fun little weekend or two in the garage. Curious if you all think this relay at the pcm was the actual issue or if it's a symptom of a deeper issue.

 

[Foggy]

I would take some time when you are doing other items and really check
the body/ frame grounds... I've not had issue but it's been
discussed a bunch on this forum. They corrode over time and cause
all sorts of very weird unrelated issues to show up

 

[petethepug]

Nice shop delving into the heated seat for you. Powertrain Control Module and diagnostic probably wasn’t that pricey.

Check your under hood fuse box attaching bolts for torque. Maybe your shop already did. If the shop doesn’t look like they were in there, check the back of the fuse box board if more issues come up.

Good truck for the winter drive. When you get a chance lower the spare tire and coat the area and the suspension control module that likes to rot out.


Oh yea, update edit/ the title to RESOLVED (WIN!)

 

[Dadnali68]

Really nice shop, not my normal but I'd work with them again. For the seats they suggested a new module. The one under the seat. Does that need to be programmed to the vehicle? I'm finding conflicting results.

 

[petethepug]

If it’s a factory new module, Yes

Preloved module, No

Gotta love 07-14. 15-20 is either a no go or reprogram.

 

[Dadnali68]

If it’s a factory new module, Yes

Preloved module, No

Gotta love 07-14. 15-20 is either a no go or reprogram.

Excellent man thank you!

 

[Dadnali68]

Issue returned. Turn the key and it doesn't start. Typically have to cycle the key for 30 to 90 seconds to get it to start. No other issues. Gage cluster comes alive, radio turns on. Just no start. Going to start with the starter relay. I've have a few other relays go bad (pcm, headlights, ac). After that might go batter cable route. Which battery cable is normally the issue?

 

[Doubeleive]

Issue returned. Turn the key and it doesn't start. Typically have to cycle the key for 30 to 90 seconds to get it to start. No other issues. Gage cluster comes alive, radio turns on. Just no start. Going to start with the starter relay. I've have a few other relays go bad (pcm, headlights, ac). After that might go batter cable route. Which battery cable is normally the issue?

check the fuse box, look for any corrosion (under the bottom)