Programming new key 2015 Tahoe

[GeorgiaWillie]

My 2015 Tahoe (LT) came w/ one key and and one keyless fob. The Tahoe uses a physical key.

I got two transponder blanks (that supposedly fit the Tahoe), and had one of them cut at a local Ace Hardware (laser, but they were cut manually). The duplicate key opens the door and turn the ignition, so I was planning to program the new transponder to work with the vehicle.

I tried the method described all over the place where you insert the known working key, turn to on for 5 seconds, turn off, remove, then insert the new key, turn to on for 5 seconds -- and it's supposedly programmed. That method didn't work.

However, if I use the original working key, start the Tahoe, turn it off and remove the key -- then immediate insert and turn the duplicate into the ignition, turn all the way to RUN, the Tahoe starts. However, the "Service Theft Deterrent System" message pops up -- even though the Tahoe is running. If I take out the duplicate, I can start the Tahoe again (immediately), but the warning keeps coming on.

At first I thought perhaps my original working key's transponder was giving the OK to start, so to eliminate that possibility, I threw the knowing working key into the backseat -- which I assume is far enough away to not cause it to be energized/found.

I wouldn't think that the vehicle would start at all (regardless of how soon/quickly I inserted a non-programmed key after immediately removing a known good key). But who knows. Anyone have success programming a new key? I guess the new duplicate could be the wrong model or something -- they're off Amazon, so it's not like they have branding/identifiers on them.

 

[Doubeleive]

on the k2 platform you have to have 2 working keys in order to program more keys, if you only have 1 working key then you need to see the dealer or a locksmith, dealer usually does it for a reasonable price mine charged me $35

**there is a slim chance that may have been something they added for 2018 and later, if so then it's possible your blank is no good

 

[GeorgiaWillie]

I had read somewhere that the 2 key requirement was added in a later year (2017/2018?) also. It just seems weird that the new duplicate would start the vehicle at all. Unless there is some sort of timer that allows any physical key capable of turning the ignition to start it if a known working transponder was used immediately beforehand. Supposedly there is some way to add new keys if you don't have any working keys that involves waiting 10 minutes for 3 iterations -- but the last thing I want to do is invalidate my known working key.

 

[exp500]

Reread the owners manual for correct steps, sometimes it's a little different than tribal explanation. Had a Ford that had to be cranked with key rather than just on,then switch back to original in 10 sec. And that was with a programmer.

 

[GeorgiaWillie]

Update here. So even though the seller where I got the keys confirmed the blanks I bought were for 2015-2016 Tahoe/Yukon... turns out they must not have been. I bought another blank pair from what seemed like perhaps a more reputable seller.

I didn't want to spend the $25/key to have the new set of keys from the more reputable seller cut without knowing that they would work, so I took the key I originally had cut and drilled a few holes through the plastic handle in an attempt to disable any transponders that key might have had. I think used that key to physically turn the ignition, but held the new blank from the reputable seller up next to the steering column. Sure enough, that worked. The Tahoe recognized the transponder (even though it was actually on a key I was holding next to the column). I followed the process outlined in the manual (which I had been doing before) and it worked flawlessly. Now to get the new-new keys cut!

 

[exp500]

Are your new keys StraTech? Good Job, thinking outside of box.