2021 Yukon - No Key Found - No Start Condition (update 11/9)

[fondupot]

Hi all, new to me Yukon acting up...63,143 miles.

I had the transmission serviced this morning at my local transmission shop, basic fluid and filter job. I also had them reset the brake life monitor because the dealer I purchased from replaced the brakes but didn't reset the monitor. After picking up the truck and driving home I made one stop at the UPS store to drop off a package, it was a short drive may be 10-12 minutes.

When I got back in the truck, the cluster says NO KEY FOUND. And then to put the key in the cup holder to start vehicle. I tried that, nothing working. The fob still worked to lock/unlock the doors, but it wouldn't start the truck.

Got an Uber to take me home to get the other key fob and bring me back. Got back, the truck fired up like no problem. Drove home (about 10 minute drive).

When I went to shut the truck down I got two messages on the cluster.
1. Key Missing One Restart Allowed
2. Vehicle Will Shut Down After 1 min

Now the truck is dead again, it wont start with either FOB.

Both key fobs got fresh batteries just a few days ago, because one was saying key fob low battery when we bought the truck.

I popped the hood and disconnected the negative battery cable and I've been letting it sit for a while. I haven't tried starting it again yet.

Wanted to post here and get some input.

Much appreciated.

 

[fondupot]

Here are the two messages I got on shut down.

 

[Cjamaco79]

Hi all, new to me Yukon acting up...63,143 miles.

I had the transmission serviced this morning at my local transmission shop, basic fluid and filter job. I also had them reset the brake life monitor because the dealer I purchased from replaced the brakes but didn't reset the monitor. After picking up the truck and driving home I made one stop at the UPS store to drop off a package, it was a short drive may be 10-12 minutes.

When I got back in the truck, the cluster says NO KEY FOUND. And then to put the key in the cup holder to start vehicle. I tried that, nothing working. The fob still worked to lock/unlock the doors, but it wouldn't start the truck.

Got an Uber to take me home to get the other key fob and bring me back. Got back, the truck fired up like no problem. Drove home (about 10 minute drive).

When I went to shut the truck down I got two messages on the cluster.
1. Key Missing One Restart Allowed
2. Vehicle Will Shut Down After 1 min

Now the truck is dead again, it wont start with either FOB.

Both key fobs got fresh batteries just a few days ago, because one was saying key fob low battery when we bought the truck.

I popped the hood and disconnected the negative battery cable and I've been letting it sit for a while. I haven't tried starting it again yet.

Wanted to post here and get some input.

Much appreciated.

Yes I see. It. should be fine after you reconnect the car battery.

 

[fondupot]

@Cjamaco79 any thoughts to what might have caused this?

Did the transmission shop resetting the brake life monitor maybe trip up the computer or something?

 

[Cjamaco79]

@Cjamaco79 any thoughts to what might have caused this?

Did the transmission shop resetting the brake life monitor maybe trip up the computer or something?

Maybe the shop disconnected a few wires with out removing the negative terminal from the battery and the computer went crazy

 

[fondupot]

I’ve had two trips now without issue. I’m gonna chalk it up to being a glitch. Hopefully that’s all.

 

[Doubeleive]

I’ve had two trips now without issue. I’m gonna chalk it up to being a glitch. Hopefully that’s all.

just throw wrench in the glove box for the battery for "next time"
mine has a opposite issue, if you disconnect the battery it won't start, so you have to disconnect it a 2nd time. OR use a scanner to clear the security module error
seems to be some kind of module handshake issue when power is interrupted.

 

[fondupot]

just throw wrench in the glove box for the battery for "next time"
mine has a opposite issue, if you disconnect the battery it won't start, so you have to disconnect it a 2nd time. OR use a scanner to clear the security module error
seems to be some kind of module handshake issue when power is interrupted.

Thanks. Strange for sure. I’ll keep an eye out.

 

[fondupot]

Update

So this morning I went to start the truck. It started fine. But the dash flashed a bunch of errors.

Service Transmission
Service Transfer Case
Service Brake System
Service Traction control System
Front collision System not active
Maybe a few others idk exactly

After a few seconds they went away. And I drove to the grocery store. Everything worked and it seemed to drive just fine.

When I got to the grocery store I got the “no key found” error. And “1 restart allowed”

Luckily, I started it back up and I went home.

When I got back to my garage I pulled in. Shut down and tried to start again. I got the “no key found” error message again and to “put the key in the cup holder” message.

Still nothing. Dead as a doornail. I have the battery disconnected again right now. But I gotta figure this issue out. Because I can’t have my wife driving this thing and leave her stranded somewhere with my 6 month old daughter.

frustrated.

Any thoughts? Gotta be some sort of module.

 

[fondupot]

Decided to replace the battery. It was the original battery from made in April 2020. Yikes.

Had the battery place test it and it came up as a bad battery. Hopefully that was all that was causing the issues.

Put a new Duracell Platinum 94R AGM in. Went in easy, fit like OEM. Started up and went for a drive. No errors on shut down. Will try a few more drives over the next few days.