Brand new, no start, no electrical

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

schmit55

Member
Joined
Aug 26, 2024
Posts
31
Reaction score
12
2026 Yukon AT4 Ultimate XL. Worked find. In my heated garage this morning nothing will light up. no connectivty with the app. nothing

onstar wants to tow it.
 
OP
OP
S

schmit55

Member
Joined
Aug 26, 2024
Posts
31
Reaction score
12
my wife left the second key in it for a day, that might have completely drained the battery!?
 

Joseph Garcia

Elite Member
Supporting Member
Joined
Aug 2, 2018
Posts
10,283
Reaction score
14,885
my wife left the second key in it for a day, that might have completely drained the battery!?
I'm not familiar with your model year, but I don't think that leaving the FOB in the truck overnight would drain the battery.
 

West 1

Full Access Member
Joined
Jan 20, 2023
Posts
633
Reaction score
1,369
Leaving the Fob in the car on the new cars does drain the battery. The car knows the FOB is there and is sitting waiting to be started with computers activated.

I would have thought it would be good for a couple days but it certainly does drain the battery as the car never goes to sleep.

Charge the battery with a battery charger, don’t jump start it.

My buddy has the new Corvette Z06. He put it in a shop to have a coating put over the paint on the front. They had the hood open and the key fob in the car for a few hours. Job done, the car had a dead battery. This car only had 1200 miles on it total since purchase.

The shop jumped the battery and started the car but the computer held the car in LIMP mode and when I checked codes for him it had 45 low voltage codes that had to be cleared before the car would run normally again.

BTW: We ran his car on a Dyno just to see what kind of power it makes. The Z06 is naturally aspirated. Factory rated at 670 HP.

It made just over 700 HP at 8200 RPM factory stock! Amazing technology.

BTW: To clear codes in these newer GM cars you have to put the car into SERVICE Mode first, then it will allow you to clear codes. You can’t just plug in and delete like you could in older cars.
 
OP
OP
S

schmit55

Member
Joined
Aug 26, 2024
Posts
31
Reaction score
12
by battery was completely dead. i had it on a trickle charger and still real low. I jumped it off my wrangler and it seems fine now. but that is some trash engineering. Same disappointment as the guy who was in charge of the buttons and screens. pure nonsense
 

Fless

Staff member
Moderator
Joined
Apr 2, 2017
Posts
16,278
Reaction score
33,631
Location
People's Republic of Colorado
Your trickle charger is going to take eons (read: days) to charge up the battery, as you found out. Most are less than 2AH chargers, and many are less than 1AH. @West 1 recommended a battery charger, not a trickle charger, and that was good advice. Sometimes the electronics don't like a jump start, and the codes can get in the way of it running correctly afterward; you were fortunate (and lucky) that didn't happen.
 

West 1

Full Access Member
Joined
Jan 20, 2023
Posts
633
Reaction score
1,369
Leaving the Fob in the car is similar to turning an old key set up to the Run position without starting. I own 2 cars now with similar FOBS and I don't like them. If you have to carry the thing around why not use it to start the car rather than have it in your pocket.
My Porsche has a FOB you need to carry and separately it has a Key that you turn to start the engine. The Key stays in the car but is removable??? Who thought that program up? You get used to it but it never make sense to me.

Glad you got it running and everything works again. The Corvette mentioned would drive after the jump but RPM was limited and it ran and shifted strange until fixed while showing many warnings on the dash.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
30,500
Reaction score
47,889
Location
Stockton, Ca.
seems kinda strange, it should at best time out rap (10 minutes) and go to sleep mode if no pedals or buttons are touched.
god forbid you wanted it to stay on otherwise and it damm sure wouldn't unless you did some scratch your head and rub your belly trick
 

West 1

Full Access Member
Joined
Jan 20, 2023
Posts
633
Reaction score
1,369
A trickle charger even with a 2 amp charge rate is zero holp to a system that will draw 20-40 amps if you leave the FOB in the car. Simple math tells you that.
 

tom3

Full Access Member
Joined
Jul 15, 2019
Posts
1,410
Reaction score
2,464
Makes me glad I have to use a key and when I turn it off, it's off. I'd probably leave that fob on the console once a week.
 

strutaeng

Full Access Member
Joined
Aug 10, 2023
Posts
1,932
Reaction score
4,173
Location
Dallas, Texas
If you had another vehicle you can take your drained battery to the local auto parts store and they will charge it for free, just go pick it up after like 6-8 hours. Kinda inconvenient, of course, but that's another option...
 

KMeloney

Full Access Member
Joined
May 2, 2009
Posts
3,455
Reaction score
704
Makes me glad I have to use a key and when I turn it off, it's off. I'd probably leave that fob on the console once a week.
You can set the truck to chirp at you when you exit the truck and leave the keys in it. HUGE help for me.
 

Tazman10

TYF Newbie
Joined
Jul 10, 2025
Posts
8
Reaction score
7
I asked that same question to the Enterprise guys and they said they don't set more than a day. He did say they have a lot of different vehicles have battery issues after setting.:2cents:
 

Johnny Fr

Member
Joined
May 23, 2025
Posts
83
Reaction score
45
If there's anything positive to be gleaned here, great to here your 2026 isn't dead for no reason. I would not have thought a fob left in the vehicle would cause it to be dead. Ours does beep at us when it's left. And agreed with the tenders or trickle chargers, my largest is 5A, that's not going to be able to bring something back from dead very quickly. For that, I'd use a 55A RV power supply (also a charger). It is regulated (has to be or RV appliances would be damaged). I've taken measurements at at 23A it was 13.2 volts as designed
 

Too_L8T

Member
Joined
Aug 2, 2025
Posts
56
Reaction score
82
I’d rather risk a dead battery than having the doors lock with my keys in it

to each their own i guess
 

Browner

TYF Newbie
Joined
Oct 15, 2024
Posts
6
Reaction score
8
Similar concern, happened 4 times always in a heated garage with fob left in vehicle, on 3rd warrantied battery dealership telling me not to leave fob in vehicle. It literally killed the battery to where charging it wasn't enough. GM Bulletin 24-NA-039 was utilized. By the way this started happening 2.5 years into ownership and I always left the fob in the vehicle. It's been about 3 weeks since last in so we'll see.
 
Last edited:

Fless

Staff member
Moderator
Joined
Apr 2, 2017
Posts
16,278
Reaction score
33,631
Location
People's Republic of Colorado
Similar concern, happened 4 times always in a heated garage with fob left in vehicle, on 3rd warrantied battery dealership telling me not to leave fob in vehicle. It literally killed the battery to where charging it wasn't enough. GM Bulletin 24-NA-039 was utilized. By the way this started happening 2.5 years into ownership and I always left the fob in the vehicle. It's been about 3 weeks since last in so we'll see.

It can be helpful to link to the referenced document:

 

Forum statistics

Threads
137,685
Posts
1,989,596
Members
102,686
Latest member
koomie98
Back
Top