Do Toyotas share coded key fobs?

Three Toyotas parked within 30 feet of each other in a crowded market parking lot. One car’s alarm went off, then #2 and then #3, almost as if they were talking to each other. Each car owner was holding their keys at the time it occurred, each frantically pushing buttons to stop the alarm riot. Any comments as to what caused this? Could they all have the same coded key fob?

Not sure, but that happened to me, parked next to a different brand of car, both of our car went off, neither of us aware of touching the panic button.

I once put in an aftermarket remote starter. At a restaurant I was able to start someone elses vehicle.

Thanks for responding. The plot thickens.

I was assigned a Ford Fusion our of my university fleet to to another institution where I was giving a talk. I pressed the unlock button on the key fob and the doors unlocked. However, the key wouldn’t unlock the ignition. I got out of the car and hit the lock button on the key fob. I then noticed the lights blinked on the car beside the one I had tried to drive. Both cars were Ford Fusions. I got in the other Fusion and the key fit. I had been assigned to that second Fusion.

Are you sure it unlocked the doors? Or maybe they weren’t locked to begin with, and you heard the doors of the other Fusion unlock?

Maybe what the OP saw was the result of some sort of radio interference?

@texases. The lights blinked on both Fusions. The cars in the fleet are always locked. I was able to get into both of the cars. However, the ignition key only worked in the one I was assigned.

Well, I suspect vintage has a lot to do with the correct answer. They have been making toyotas for a long time. In that time, the electronics involved in the remote systems have evolved significantly. Back in the day, there were just a few set frequencies used. Today they use rolling digital codes like the garage door openers so far more combinations and less likelihood of having the multiple cars respond to a single remote.

My guess is that there are probably a finite number of codes they choose to use between fobs. Lets say they have 10 codes they use and reuse… I would imagine the mfg’s figure, what are the odds your fob will be the same as a nearby vehicle of the same make and model.

Someone above my pay grade and far smarter than me most likely provides these “Odds” as a mathematical certainty and the mfg decides which odds they like best and roll with it.

In the future I can see this issue going away with more computing power. Then again this is all guesswork on my part, so what do I know. But its obviously possible to have an identical fob code for a specific vehicle, demonstrated by your example

If I read the post correctly the alarms went off in a sequence rather all at the same time . I think when the first one went off by mistake the others thought it was theirs and started pressing the alarm buttons to shut it off .

I once activated one vehicle getting the keys out of my pocket and then pressed the button on the other one . I had both vehicles making noise at 11 O’clock .