Our mk1 '05 Superb is telling me "check brake lights", but on inspection (even immediately when it happens) all three lights are on and appear fine. I've replaced both light bulbs (not the strip) and the garage can't find anything obvious. I've noticed that it tends to do it when it's been raining or generally damp, but I don't suffer from water ingress at the front (that's been checked already).

Any ideas on where to look next?

Just FYI, did you replace the bulbs with LED ones?

First of all, check / replace brake light switch in drivers footwell. Also, if you did put in LEDs instead of bulbs, they will cause warning as there is insufficient load.

Other than that, cabling at this time of year can cause problems due to water condensation. Undo/redo both plugs at the light clusters, perhaps there is a poor connection.

First of all, check / replace brake light switch in drivers footwell. Also, if you did put in LEDs instead of bulbs, they will cause warning as there is insufficient load.

Other than that, cabling at this time of year can cause problems due to water condensation. Undo/redo both plugs at the light clusters, perhaps there is a poor connection.

I'll check the brake light switch and plug connections to the light clusters. Both bulbs were replaced with new filament bulbs (not LEDs).

I had this 4 years ago. Turned out the high level brake light was intermittently faulty - every time the warning came on I would check the lights and all three worked, it was only noticed when my wife following behind me on a journey one day commented that it wasn't always lighting up with the main lights. What the actual fault was I don't know, as it was replaced for a new light unit in the last days of warranty. Been fine ever since.

cheers