What would cause keyless entry not to work?

[wolf1340]

2017 Yukon
Removed rear seat. Now keyless entry does not work. Tried both remotes. If this was not caused by removing the seats. Then what else could it be. Message pops up that keyless needs service. Lock and unlock with button still works. So does keyless start.

 

[MSgt Chevy]

I would think a ground doesn’t have a good contact. But I may be wrong

 

[Kpwweb]

Have you tried re-installing the rear seat and see if it works again? It shouldn't, it should just be a red herring. A lot of people have removed the rear seat with no impact on keyless entry, including myself.

By not working, do the doors not lock with keyless entry, not unlock with keyless entry, or both?

Do you get a message on the DIC that a door is open? Could be a wonky door switch.

Lastly, do you have an enhanced alarm system that was optional on these vehicles? Just a guess, but it could be confusing the interior sensor if so? (Shouldn't make any difference, but we are grasping at straws here).

I think you will have to go through a process of elimintation to track it down.

 

[wolf1340]

Have you tried re-installing the rear seat and see if it works again? It shouldn't, it should just be a red herring. A lot of people have removed the rear seat with no impact on keyless entry, including myself.

By not working, do the doors not lock with keyless entry, not unlock with keyless entry, or both?

Do you get a message on the DIC that a door is open? Could be a wonky door switch.

Lastly, do you have an enhanced alarm system that was optional on these vehicles? Just a guess, but it could be confusing the interior sensor if so? (Shouldn't make any difference, but we are grasping at straws here).

I think you will have to go through a process of elimintation to track it down.

No message saying doors are open. Just message saying service keyless system.
Doors will lock/unlock if I press buttons on fob. But will not unlock when I touch the door handles.
Haven’t had a chance to plug seat back in yet. Should be able to tonight.

 

[wolf1340]

Also I might not be calling it the right thing. I think it’s called passive entry.

 

[dbbd1]

You didn't crush a fob while removing the seat? Accidentally leave a fob inside somewhere? I'm just throwing it out there...

 

[wolf1340]

You didn't crush a fob while removing the seat? Accidentally leave a fob inside somewhere? I'm just throwing it out there...

No. I have both fobs.

 

[Doubeleive]

you probably need to hook a scanner to it or take it to the dealer so they can scan it, with the keyless entry on these trucks now it is all encrypted, maybe it just lost the sync somehow.

 

[Dooba]

Have you checked the vehicle settings? Theres an option to disable passive door unlock & lock, maybe the system reset and turned it off?

Have a look:
Go into settings in your touchscreen
Choose vehicle>remote lock, unlock, start>Passive door unlock (or lock, check both)

Hope it helps.

 

[wolf1340]

Have you checked the vehicle settings? Theres an option to disable passive door unlock & lock, maybe the system reset and turned it off?

Have a look:
Go into settings in your touchscreen
Choose vehicle>remote lock, unlock, start>Passive door unlock (or lock, check both)

Hope it helps.

Could be a possibility. But, if it got turned off somehow. It wouldn’t have a “Service Keyless system” message pop up.

 

[Dooba]

Hmmm

Could be a possibility. But, if it got turned off somehow. It wouldn’t have a “Service Keyless system” message pop up.

I may have jumped the gun there, haha!
No harm in looking, plus I’ve checked some corvette forums that complain about the same thing in the c7. Apparently if you put it in the little cubby in the centre console it’ll kinda relearn it and fix itself?

Worst case is a trip to the dealer, you’re under warranty and they can’t blame you for it without proving that removing the third row broke it.

 

[Fless]

Have you tried re-installing the rear seat and see if it works again? It shouldn't, it should just be a red herring. A lot of people have removed the rear seat with no impact on keyless entry, including myself.

I think you will have to go through a process of elimintation to track it down.

^^^^ THIS. It's an easy way to know if the issue is caused by removing the seats, and cured by reinstalling them. Quick and easy test.

 

[wolf1340]

Problem solved. Put seat back in to see if that was the issue. While pugging it in I could hear something hitting floor. Looked under carpet and found a wire unplugged. Looks like it goes to an antenna for the keyless stuff. Looks like a little square box. Plugged it back in and all is good. Took seat back out. I must have unplugged it while pulling on the seat plug in. It’s tied in to the same harness.

 

[Sonnie kim]

Omg! I am so glad people post stuff like this online to search, i had the same problem as you, i have a 2017 gmc yukon slt and i removed the third row seats but didnt have any problems. But a few months later i had the same problem as you. And couldnt figure out what it was until i read this post! Hope it helps others who take out their third row seats. Its very easy to pull that cable out and not know it since its under the carpet and connected to the wire for the third row.
Also side note i took it to the dealer who wanted to replace the door handle and the antenna and said it would cost 1000 dollars to fix. I told them no, i would rather just use the key fob, you would think they would do a better job, this is the third time i found an answer on a forum that has saved me.

Problem solved. Put seat back in to see if that was the issue. While pugging it in I could hear something hitting floor. Looked under carpet and found a wire unplugged. Looks like it goes to an antenna for the keyless stuff. Looks like a little square box. Plugged it back in and all is good. Took seat back out. I must have unplugged it while pulling on the seat plug in. It’s tied in to the same harness.

 

[sealandsky]

Have you resolved the issue yet? Curious as to what caused it?

 

[Petruxa]

I had the same issue, here is the plug and the sensor under rear seat.

 

[sealandsky]

I was told by my local GMC dealer (so maybe incorrect) that there is a passive entry receiver near each entry point to the vehicle. At least on the front and middle seats the receiver is mounted underneath each seat. It's possible that your rear receiver is mounted under the rear seat.

 

[hnavarro1]

I had the same issue, here is the plug and the sensor under rear seat.

View attachment 245881 View attachment 245882 View attachment 245883

Hello, I had the same problem, suddenly the “Service Keyless system” appears at the dashboard, I get the code b3134-05 but I can't find the antena no 5 until I saw your photos. I access it from the 2nd row without remove the 3rd row, it's under the mat, it was bad connected, I reconnected it and now everything works fine. thanks a lot.

 

[Daddydave]

I had the exact same issue and dreaded having to take it to the dealer. I took the 3rd seat out for a road trip and half way through the handle button stopped working. Many posts are how to enable/disable passive entry. It wasn't until I found this board that I learned of the little black box under the padding. And sure enough, that was the issue!

Petruxa, a big thanks for your post and pics!

 

[Ghost10]

This might be horse shit, snake oil but when I purchased my used 18 Tahoe the dealership which btw is VERY popular, Trendy always in business and has great reviews told me every single part on the vehicle is traceable and that removing the seat could trigger a anti theft lock out or some kind of hocus pocus.