Originally Posted by
Eggman
If I understand correctly, ETACS monitors the brake lights. If the lamp burn out, its an error that needs to be addressed.
I recall other posts of owners replacing their incandescent lamps with LEDs and it causes problems like this. In benwerks case, the problem seems to happen with incandescent and LED lamps. Maybe there is something else related causing this? I would inspect the lamp socket carefully for corrosion or other signs of damage. Also, it would be helpful to know if there have been any changes to the wiring back there, such as a backup camera (I've done this) connected to reverse lights or a trailer harness. Other than that, it's worth taking another look at the bank of connectors behind the left-front kick panel for signs of corrosion. Fummins has noted that sometimes it's hard to see water damage, but it has caused him lots of similar headaches and it is often where he goes first for troubleshooting & diagnosis.