Have no idea what I did this evening but got in the truck to go to dinner and it won't crank, giving me a message about 'service anti theft system.'

I have been relentlessly googling and have found numerous procedures but none of them have worked. I unhooked the battery for 30 min and was able to get it to start up. Thinking everything was OK, I stopped and got gas a mile from my house and now it won't start again. I once again unhooked the battery and waited 30 minutes but it didn't work this time.

Most procedures mention using the key in the ignition but my Yukon is completely keyless (fob only.)

Anyone been through this? Hoping I can get it cranked to get home so I can deal with it tomorrow.

How old is your battery?

Bad keyfob battery maybe?

If you have remote start does it work? I've seen weak battery in FOB cause this. Will 2nd FOB work?

If you have OnStar, call them. They may be able to help.

I don't know how old the car battery is. I've had the vehicle 2 years but it's a 2015 model.

I replaced key fob battery. Old one and new both worked to lock and unlock the car just fine.

Remote start will not work. And I only have one fob.

I don't have OnStar.

quote:

Originally posted by Balzé Halzé:
How old is your battery?

This is what I'm thinking as well. The vehicle battery may be weak, disconnecting the first time, it might of recovered enough to start. Low voltage can cause strange no start issues, try disconnecting it again, then before starting it , try jump starting it.

Sit rep. I got an Uber home and grabbed my other car and went down to see if it would jump. It did. Drive it home, didnt turn it off, picked up my wife, and we went and got her car so both vehicles are safe at home.

Mine is on a battery charger for the night. My charger will do an alternator test and it says it's good, though it's not 100% reliable.

I am beginning to think that this never was an anti theft thing but was always a battery thing. Perhaps an old/bad battery or perhaps I left something on drawing amps from the time I got home (530p) to the time I tried to leave (8 pm.)

When I unhooked the battery the first time, I also hooked the charger up for about 10 minutes. Perhaps that was enough for one crank. Then I only drive it about 2 mi to the gas station which wasn't enough to charge off the alternator.

I guess we'll just have to see in the morning.

If your key has a security resistor on it, clean it with alcohol.

As others have said I'd start with the battery.

I owned a 2015 Yukon XL with the 6.2 One day it started fine and we drove about 5 minutes across town with no apparent issues.

Sitting at a stoplight we got all kinds of alarms/warnings and it just dies. Dead right there. Won't start, no accessories, dim dash lights.

Get it pushed of to the side of the road. Let my NOCO jump pack sit on it. Nothing. Tow truck shows up and he says lets try my jump booster. Starts right up and we drive back home, no issues.

I put it on the battery charger overnight and the next morning starts up and drives for a bit and then starts acting weird. Luckily I was only a mile or so from an Interstate Battery dealer. They said I likely had a cell in the battery that was starting to go giving me erratic voltages. They said that all the gadgetry on these new vehicles puts a tremendous load on the charging systems and they don't handle voltage sags and surges well. Changed the battery and the issues went away.

Yes, I'd start with replacing your vehicle's battery and go from there. It's likely old enough where it's due for a change regardless. Indeed it probably has nothing to do with the theft device at all which is why I asked about the battery initially.

Charged the battery all night but this morning the charger said "service or replace battery." So I jumped it and drove up to Napa and put a battery in.

(They no longer do install, apparently, but they will loan you the tools to do it. No big deal but I wish I hadn't showered and dressed for worked beforehand.)

Everything is fine now... all dash warnings are gone. Frustrating but glad it was something easy. The old batter was a Napa Premium 790 CCA from 2018.

5 years on a battery is about the limit anymore, there is a constant drain on them with all the electronics in cars today.

Just about anytime you see electronics going wonky its voltage, either battery or alternator, used to be you' see the tach jumping, speedo off, other analog gauges as well and you'd know.

Autozone and Advance Auto Parts still change batteries out for free.

I bought a new truck last October. All was fine until about January when it started acting like the battery was dead. Wouldn't start after sitting for a day or two. I could charge the battery and it was fine until the next time I let it sit longer than a day or so. The local auto parts store put their tester on it and it said the battery was good. The dealer, 50 miles away, said if I wanted to have it handled under warranty I would have to leave the truck with them for "a couple of days" so they could "run a test on the battery". I think they just didn't want to deal with it. I went to a local tire shop and bought a new battery (they installed it), and it's been working great ever since.

quote:

Originally posted by YellowJacket:
Charged the battery all night but this morning the charger said "service or replace battery." So I jumped it and drove up to Napa and put a battery in.

(They no longer do install, apparently, but they will loan you the tools to do it. No big deal but I wish I hadn't showered and dressed for worked beforehand.)

Everything is fine now... all dash warnings are gone. Frustrating but glad it was something easy. The old batter was a Napa Premium 790 CCA from 2018.

How long did it take? Whoever designed that location needs to be punched in the face.
A battery change should be a quick removal of a hood down and the two terminal connectors.
Having to take that cross bar reinforcement makes it a far larger gigantic pain that need be.
My wife’s died in dead of summer in the garage was about 105* in the garage and I was in full uniform. Finally ended up taking off my duty belt to get all that crap out of the way.

I put in a Northstar X2 AGM cranking/deep cycle battery. We have the fully loaded model so all those lights the boys like to leave on as well as the video screens, wireless headphones, constantly drawing power.
Thankfully that battery is still going strong.

I swap out batteries every three years. With our winters its just good preventative maintenance.

quote:

Originally posted by Black92LX:

quote:

Originally posted by YellowJacket:
Charged the battery all night but this morning the charger said "service or replace battery." So I jumped it and drove up to Napa and put a battery in.

(They no longer do install, apparently, but they will loan you the tools to do it. No big deal but I wish I hadn't showered and dressed for worked beforehand.)

Everything is fine now... all dash warnings are gone. Frustrating but glad it was something easy. The old batter was a Napa Premium 790 CCA from 2018.

How long did it take? Whoever designed that location needs to be punched in the face.
A battery change should be a quick removal of a hood down and the two terminal connectors.
Having to take that cross bar reinforcement makes it a far larger gigantic pain that need be.
My wife’s died in dead of summer in the garage was about 105* in the garage and I was in full uniform. Finally ended up taking off my duty belt to get all that crap out of the way.

I put in a Northstar X2 AGM cranking/deep cycle battery. We have the fully loaded model so all those lights the boys like to leave on as well as the video screens, wireless headphones, constantly drawing power.
Thankfully that battery is still going strong.

Took me about 15 minutes all told I guess. The cross bar is annoying. If I had a driver it would have been quicker but all I had was a ratchet.

To get the old battery (Napa) out I also had to loosen the coolant reservoir and move it a bit. The new battery (AAA brand) is about 2" shorter so it went in easier.

Nice to see you got it fixed. BTW, I don't know about out your way but around here O'Reilly's and Auto Zone will still install batteries. Good to look over their shoulders though, if you know what I mean.

quote:

Originally posted by yanici:

O'Reilly's and Auto Zone will still install batteries. Good to look over their shoulders though, if you know what I mean.

Definitely watch them. I had a battery showing signs of age, so I bought one at Batteries Plus, free installation. Car wouldn't start with new battery, they claimed "bad alternator."

I asked to borrow their wrench for a minute, I tightened the clamps properly on the battery posts, and all was well with the world (or with my car, anyway).

The battery installer guys looked amazed. I told them that I had not reached 86 years old without learning something.

quote:

Originally posted by yanici:
Nice to see you got it fixed. BTW, I don't know about out your way but around here O'Reilly's and Auto Zone will still install batteries. Good to look over their shoulders though, if you know what I mean.

Interstate Batteries here will install, too.

flashguy