When I bought my Porsche Boxster, the seller gave me two keys, noting that the lock button on one had stopped working some time ago. Always up for a challenge, I dove in and found a fix that was cheaper than you might imagine.
When you buy a used anything, you expect that some parts of your new purchase are going to be…well, used. In some cases, those parts may be used up, to the point where repairs or replacements are necessary.
That was the case with the 2001 Porsche Boxster 986 I bought over the summer as a pandemic project. Nothing on the car was particularly broke-ass, but there were a few niggling issues that warranted my attention.
The first of those issues I tackled was with one of the two keyfobs that came with the car. The 986 combines its blade key and remote unlocking fob in a single unit, with those on my model year featuring three buttons on one side. The two smaller buttons pop the front and rear trunk lids, while the larger central button does the doors and arms/disarms the alarm.
One key worked without issue, with all of the buttons doing their thing as expected. The second one, however, had a problem. The two storage compartment buttons were working just fine, but pressing the main door lock button resulted in no joy.
Now you might think that a keyfob remote is a fairly inexpensive thing to replace. Hell, I’ve replaced them on Toyotas for less than $20, and they’re easily found on eBay.
The problem with my Porsche’s keys, though, is that they are part of the car’s rather complex M535 security system. In addition to the locking mechanism activating the alarm, the system includes an immobilizer circuit that is driven off the pre-matched keys. The ignition switch is surrounded by an induction coil and that energizes a pill transponder in the key. The pill then sends a unique signal to the car that enables the ignition.
Any new key/fob would require an astoundingly expensive programming process that would have to be carried out at a Porsche dealer or specialist.
I wondered if a cheaper solution might be available. For the particular problem with my Porsche’s key, it turns out there was. In fact, the fix for my key cost a grand total of $7.51, and that included shipping from England to Los Angeles.
Deducing the fix required opening up the fob end of the key. This is a fairly simple process and is also necessary to change the disc battery when it goes flat.
There’s a joint just above the blade where a stout fingernail might be placed to pop the two sides apart. The major guts of the transmitter are contained in the free half of the fob while the aforementioned immobilizer pill is nestled in the half with the blade. A rubber gasket between the two seals out dirt and water and whatnot.
Once the two sides were separated, it was a small matter to slightly bend the three retaining tabs, releasing the tiny circuit board from the shell. This is unnecessary if your goal is just changing the battery, but I needed to see what was going on with the under-button switches on the other side.
Pulling the guts out proved a surprisingly simple task, without the chattering of loose buttons that accompany the effort on some other fobs. I’m looking at you, Honda.
Looking at the side opposite the battery holder I immediately found the problem. If you look at the picture above you’ll note that the center switch looks decidedly different from the other two on the board. You’ll also note a brass rectangle that looks completely out of place.
That brass rectangle is the connector for the main lock microswitch. What’s left of the switch itself is just the plastic base and detached rubber plunger and surrounding metal cover. Those were all loose and no amount of persuasion was going to put this tiny Humpty Dumpty back together.
Fortunately, eBay came to the rescue. As it turns out, the switches inside the Porsche fob are fairly common pieces and not made from moon dust and Black Forest fairy farts, as one might imagine.
A quick search of everybody’s favorite auction site turned up a seller in Great Britain with the necessary button switches delivered for the aforementioned $7.51. That was suitably cheap, and after buying them and having the internet convert my dollars to British pounds, I was off to the races.
Once I received the buttons through Royal Mail Post (how posh!) I got out my soldering equipment and took to de-soldering the old switch and tacking in the new one.
It was a pretty straightforward job, as the buttons are held in place by a single solder joint on each of the short sides. I first desoldered those using my pencil iron and de-soldering wick. I then fluxed the contacts and soldered one of the new switches in place.
The whole job took about 10 minutes and would have gone quicker if I hadn’t drained two cups of coffee beforehand, which led to an annoying case of shaky-hand syndrome.
Once I had the button securely in place I went out to the driveway and tested the bare circuit board on the car. The doors locked and unlocked with their familiar satisfying “ker-klunk” through multiple presses. The test successfully completed, I went and put the fob back together.
My Boxster now has two fully functioning keyfobs. This may seem like the triumph over what was nothing more than a minor annoyance, and to be perfectly honest, that’s all it is. Still, in automotive wrenching just as in everything else, it’s the little things that make life worth living.
It’s also very satisfying to have brought back a failed part of my old Porsche, and especially to have done so without breaking the bank.
Next time: we tackle cup holders and console bin locks!
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