A Key Repair

 

Many General Motors and other brand cars come with a remote key FOB with an integrated key that flips out in ‘switchblade’ fashion. My car came with key FOBs of this type. The key blade is held in place with a tiny roll pin that can work loose over time, and I had to super glue both of mine into place. Shortly before doing this to the first of the two keys, I had bought a pair of replacement shells online, with the idea of transferring the circuit board and key blade over to it, but the super glue proved easier, so I never used them—until now. The super glue solution worked well for a couple of years, just the tiniest droplet at each end of the roll pin, until I noticed that one of them had developed a stress fracture, just above where the key blade slips into place.

Facing an imminent structural failure, which is quite common on keys of this design, along with tearing of the rubberized buttons, I decided it was time to transplant the operational components of the cracked key fob over to one of the new shells. This is one of several options available. The list below may help you decide which is best for your needs:

Complete replacement—This is the most expensive option, but requires the least work on your part. Replacement key FOBs are readily available online for between $8 and $20, and you can have the key blade cut by a locksmith for an additional fee. This will be far less expensive than purchasing one from a dealership. Pairing the new FOB to your car can be done without any specialized equipment, as long as you have a working, factory original key, at least that's the way it works on many GM cars. Your mileage may vary.

Key blade swap—You can save the cost of having the key cut (about $20 in my case) on a replacement FOB by swapping the key blade from your old key FOB over to the new one.  Just tap out the roll pin, remove the blank key blade, replace it with the original, and press the roll pin back into place. You will still need to pair the remote with the car, but you will also have an extra remote, albeit without a key. You might put the blank key blade away for safekeeping, just in case you ever need to get it cut.

Component transfer—Empty key FOB cases with uncut blades are also available for about half the cost of a complete FOB that is ready to cut and program (around $5). This option allows you to swap the key blade and circuit board from the original remote into a new shell. This is the least expensive option, but the most labor intensive. This is the option I chose when the hinge on one of my original remotes started to give way.

Moving the key blade over was the easy part. I used a small precision screwdriver and a hammer to tap the roll pins out of both the damaged FOB and the empty shell, which included a blank key blade. The original key blade was a snug fit, but it went in and lined up perfectly, allowing me to press the pin into place with a pair of needle nose pliers. I first grasped the pin straight on and pushed it into the hole, then squeezed it the rest of the way with the jaws of the pliers.

The empty shell came apart easily, prying and twisting it with my fingers, but the original was not at all designed to come apart, which essentially necessitated the destruction of the original shell to extract the circuit board. In other words, getting inside of it marked the point of no return.

Before I made that decision, I had another one to make. I could either break up the case on the original remote to get to the circuit board and put it into the replacement case, along with the key blade, or I could get a replacement remote with a circuit board already installed, transfer the key blade only, and program the remote, leaving me three functioning remotes, two of which have keys. I ultimately decided to try the first option, since I already had the empty cases on hand.

Tearing into the original, factory remote was a challenge. Unlike the replacement units, the case is not intended to come apart, so one must be fully committed to this course of action. Once I started trying to get it apart, I quickly went from being hesitant that it was what I wanted to do, to be obsessed with the idea of getting it apart, no matter what it took.

Before I began tearing into it, I had already transferred the cut key blade to the new housing. This left me some room to slide a flat blade screwdriver in above the hinge, for maximum leverage to twist and pry, without endangering the circuit board inside. Mine eventually gave way, but the two halves of the case did not come apart cleanly. I eventually tore away enough of the back half (the one that does not have buttons) so that I could slide the circuit board out. At that point the original case was trash, although I did save the battery cover to have as a spare.

The final step is to put everything into the new case. There are essentially five parts that go inside the case—the circuit board, the key blade and hinge assembly, key blade release button, a spring, and a battery clip. Getting all of these parts properly positioned inside the case and tensioning the spring so the key blade pops out when the release button is pressed, and then snapping the case together, is a challenging proposition to say the least. The steps to do so are below. For purposes of this discussion, The side of the key fob where the buttons are located will be referred to as the ‘front’ and the side with access to the battery compartment will be referred to as the ‘back’.

1. With all necessary components extracted from the original, factory FOB, open and disassemble the replacement case. This will be far easier than opening the original unit, and should require no tools, only fingers.

2. Position the circuit board in the back half of the case, making sure the battery clip is properly positioned underneath it. The circuit board is asymmetrical, so it only goes in one way.

3. Position the spring in the back half of the case so that the end with the ‘ear’ extending from it catches on a little tab inside case.

4. Insert the button into the hole in the ‘hinge’ of the key blade assembly, making sure the three tabs of the button properly align with the slots in the hinge. It only goes one  way.
   

5. Lay the key blade and button on top of the spring so that the key is in the open position.

6. Tension the spring by turning the key blade counter-clockwise 1.5 turns until the key blade is in the closed position.

7. Holding the key in place so that the spring does not escape, bring the two halves together and snap into place. This will be challenging, as the circuit board will inevitably shift a bit. You can nudge it back into place with your finger through the battery compartment, keeping pressure on the corner where the key blade attaches to keep tension on the spring.

8. Once everything snaps into place (some replacement FOBs will also have a screw that will ultimately be hidden by the manufacturer’s emblem) insert the battery, snap on the battery cover, and test the remote. The buttons and the key should work as before.

At this point, I have three FOBs for my car—an unmolested original, a ‘frankenFOB’, which contains the original circuit board and key blade in a new enclosure, and a replacement FOB that I had cut and programmed. I also have a second empty replacement shell, should I ever need it. I had both the replacement FOB and the two shells on hand, so the only expense involved was having the blade cut on the replacement FOB. Had I realized how easy it would be to swap the key blade over, before I got the key cut, I might well have done that and saved a little money.

At this point, I am carrying the replacement FOB and using it on a daily basis. I prefer using it because the circuit board is of an updated design that requires the trunk release button to be held down for a second or so before the trunk opens. This effectively eliminates the common problem of spontaneous trunk opening. The frankenFOB is now the go-to spare and the remaining original is effectively retired, as its buttons are heavily worn and I’m not eager to perform another component swap anytime soon. 

UPDATE 1 Aug 2023: It's been almost three months since my adventures with the key FOBS. I've spent part of that time carrying the replacement FOB and the rest of the time carrying the FrankenFob. Both work quite well, and I've noticed one added benefit. Before I did all that, I was frequently finding my trunk open when I went to start the car. This is apparently a common problem with my make and model, and GM even came up with a programming fix to require the user to press the FOB's trunk release button twice to open it. I've found that carrying either the new or the renewed FOB, this doesn't happen anymore. I can only conclude that the buttons on both the replacement FOB and the replacement case are stiffer than the original, making them less susceptible to accidental pressings in my pocket. Since this was not initially a problem when I first got the car, I can further conclude that the buttons on the original FOBs weaken over time.