incorrect bulb failure warnings

[sidewaze samm]

On the way home tonight - so that's sitting in a big queue, then - my peace was shattered by the discordant warning chime and appearance of a multi-dot message, kindly informing me of brake light failure. Not the message that's exactly welcome at dusk on a Friday evening with another 8 miles to go. So, with a sigh of resignation I put my foot on the pedal to see if I can see a reflection of brake lights on the car behind. Nothing - but it's not that dark yet. But a little later I notice a faint glow around the high level lights in the rear window - so at least I've got some brake lights.

Get home and check it out. All lights are working. And that means every single bulb in the high level brake light too. Odd.

Then I remember another warning I had a month ago. Getting in the car at night, I started the engine and turned on the headlights to immediately get a warning about a bulb failure. Everything seemed to work and I forgot about it until today.

So, guys. Any ideas? Cause for concern?

[Surrey White]

I had that a few years ago on the Octy. I had just changed one of the tail/brake lights a few weeks previously. It turned out to be a faulty bulb where the two filaments were touching when they got warm.
Check the brake light - OK.
Check the tail light - OK.
Turn the lights on at night then use the brakes for a bit and the two filaments expand and touch causing a bulb failure warning. Get out and check and everything seems OK again.
My local garage suggested just swapping the bulbs immediately when I called him as he'd seen this a few times before.

Worth a try.

[westerdam2]

Originally Posted by sidewaze samm

Then I remember another warning I had a month ago. Getting in the car at night, I started the engine and turned on the headlights to immediately get a warning about a bulb failure. Everything seemed to work and I forgot about it until today.

So, guys. Any ideas? Cause for concern?

Not claiming this is the answer but I had similar problem 2 years ago on my 03Superb Elegance. It caused all sorts of probs but was eventually resolved.

Transpired the warning was triggered by the self-leveling headlights failing to do their bit. All bulbs were working normally but the sensor(s) had gone in the automatic self-leveling system. Not hugely expensive to sort but a prob not immediately resolved by garage - or the well-meaning souls on this site who offered all sorts of theories.

Worth a try, if only for elimination purposes.

[sidewaze samm]

Have now discovered that the high level lights in the rear window are working intermittently. (Are they seperate bulbs? - if so, with the brakes applied, they're either all on or all off. At least that's what I've seen) As far as I can tell the brake lights within the main light clusters work all the time - that is, I'm not aware they don't.

So any ideas what might cause this? How do you get to the high level unit - from inside the boot I can check that a wire is in place but can see no means of getting into the unit itself from the underside of the parcel shelf.

It's due for service, but I'd like to get an angle on it before it goes in.