Some newer vehicles rely on measuring resistance on light circuits to determine lamp operability. The resistance of the LED lamps you are using may be triggering the lamp inop warning (rapid flashing). If that's the case the only solution is to find an LED that presents the same resistance as a standard incandescent lamp, or add a resistor to the circuit.
If you check i'm sure you will find it's only the inside is flashing quicker the outside is ok. When i changed to LED brake bulbs did the sane thing.
Running LED brake light for awhile now and just ignore the rapid flashers outside is fine, Just check your brake lights once in a while make sure one not out,
In "the old days", we could replace the turn signal flasher with one that supports the low resistance of LED bulbs and would also work with incandescent bulbs (filament). I guess our BS's don't use flashers/relays like this?
I don't think these cars use analog devices like that. I'm pretty sure the "flasher" is a piece of computer code.
It figures!
As with you, I had a brake light go out, so I did the right thing and replaced all of the incandescent bulbs.. You know, like Ford should have installed from the factory. The first surprise I got was the drivers side cover panel (hides the tail light mounting hardware) had a broken tab, so someone has been here before. Next was the rapid flashing, but after checking front & rear, they only flash fast on the dashboard. Frankly, as long as they are working, I could care less
