2018 yukon slt no start

[Doubeleive]

I have done both. Have had it Towed and also tried to start it for 20 min by pushing the push start repeatedly. Eventually it started after 15 min of pushing the push start button repeatedly. When it does not start, the first push of start button makes the dash come on normaly. Second push everything turns off. When it acts up like this, i did notice the horn will not beep when the key fob is pushed 2x to lock vehicle. And I also noticed, i went to open the back hatch, which opend fine (from pushing the hatch latch button itself (not the key fob). But when I went to close the hatch by pressing the button on the inside of the hatch, it would not close as if there was no power.. I had to manually pull it down to close. Not sure if that means anything but I figure at this point, anything out of the ordinary I should mention.

I would start with checking the battery (have it load tested) many auto parts places will do it for free, as well as sears or any battery shop.
if the battery checks out, then have the battery cables looked at or checked, they can ohm check the cables and do a voltage drop test. the battery cables can do weird things even based on the ambient temperature if they are no good, also the battery cables have been known to corrode on the inside and look fine on the outside, not saying this is the case here but it should be noted. if it drives normal and operates normal other than those problems mentioned I would lean towards it being a power problem. maybe a bad ground. that's where I would start.
on my 2012 one of the signs of having low power I have noticed is the rear hatch will not close properly, that may not mean anything here but it is one thing I have noticed, these trucks are real finicky when the voltage is low and will do all kinds of weird stuff.

 

[SPRINKS]

I would start with checking the battery (have it load tested) many auto parts places will do it for free, as well as sears or any battery shop.
if the battery checks out, then have the battery cables looked at or checked, they can ohm check the cables and do a voltage drop test. the battery cables can do weird things even based on the ambient temperature if they are no good, also the battery cables have been known to corrode on the inside and look fine on the outside, not saying this is the case here but it should be noted. if it drives normal and operates normal other than those problems mentioned I would lean towards it being a power problem. maybe a bad ground. that's where I would start.
on my 2012 one of the signs of having low power I have noticed is the rear hatch will not close properly, that may not mean anything here but it is one thing I have noticed, these trucks are real finicky when the voltage is low and will do all kinds of weird stuff.

Very good information man! I have honestly learned more from you then the dealer/ GM has told me. I should give them your number and maybe you can teach them some new tricks. Much appreciated for all the ideas! I will certainly be letting them know and doing some myself when the time comes!

 

[Doubeleive]

Very good information man! I have honestly learned more from you then the dealer/ GM has told me. I should give them your number and maybe you can teach them some new tricks. Much appreciated for all the ideas! I will certainly be letting them know and doing some myself when the time comes!

they know all this stuff, they just won't check it all under warranty, gm only pays them to follow certain procedures if those procedures reveal nothing then they do not go any further. they will if you are paying out of pocket for the tech time usually $100-160hr in which case you can request them to do whatever you want.
they only check what they see happening as a code or is visibly broken. I took my truck in with a bad water pump that I could wiggle by hand, they said we'll have to check it out, lol
i took the service guy out popped the hood open and showed him, they had it fixed the same day. It's ridiculous sometimes.

 

[SPRINKS]

they know all this stuff, they just won't check it all under warranty, gm only pays them to follow certain procedures if those procedures reveal nothing then they do not go any further. they will if you are paying out of pocket for the tech time usually $100-160hr in which case you can request them to do whatever you want.
they only check what they see happening as a code or is visibly broken. I took my truck in with a bad water pump that I could wiggle by hand, they said we'll have to check it out, lol
i took the service guy out popped the hood open and showed him, they had it fixed the same day. It's ridiculous sometimes.

Little update. GM engineers are now going off of a similar issue they had in 2018 and suggesting to replace the fuse block as they have been known for corrosion and cause similar issue. My vehicle had this fix done back in 2018 at 7000km when it was new ( I did not own the vehicle then( bought the vehicle this year 2022). So basically replacing the same thing they did years ago... not sure if it's going to be the fix but time will tell. Currently waiting for the work to be done. Hoping it is the fix or GM does a buy back of the vehicle. I highly doubt I will get back what I paid for it if that's the case.

 

[Cody27]

Good morning, did this end up resolving your issue? I'm having the exact same issue with my 2015 yukon xl denali and I've tried everything mentioned in numerous threads with no luck. Really want to give it all I have before paying the dealer to screw me around....