Streange electrical gremlins

[BlackCat3000]

2009 Superb SE 2.0 CR 170, 22,500 miles.

Just got into my car again this evening after driving home (when everything was fine) and had the following problems:

1. The courtesy lights came on only for a couple of seconds.
   
2. The dashboard display indicates a blown bulb.
   
3. The MFD display cycles round "Check front right indicator bulb", "Check front left inicator bulb" and goes through every bulb in the car.
   
4. The indicator repeater in the dashboard flashes and ticks at double speed, suggesting a blown indicator bulb.
   

However, all bulbs appear to be working, so I'm at a loss to explain any of this. Any ideas, anyone?

Thanks, BlackCat3000

[ddyer79]

I had this a couple of times on my 2009 170 CD Tdi Elegance Twindoor over 3 years of ownership and 60K+ miles.

Just pleased it didn't happen more often.

Next time I started the car it was fine.

Canbus gremlin caused by faulty reading from first bulb check was my assumption - triggered the strange behaviour.

[BlackCat3000]

Thanks, DDYER79, it's reassuring that others have seen this and that it sorts itself out.

Sure enough, this morning it was almost back to normal - everything is ok now except the coming home & leaving home lighting functions, which seem to have stopped working. I've been through the setup in the MFD and disabled/re-enbabled them without success. Maybe they'll just re-appear in the next day or so? If not, I can wait until the next service is due and have it looked at then.

[jonnie5]

Sometimes the filament in a bulb can fail but when it cools down the filament settles back down a rejoins the circuit again. It's like the filament opens and closes with the heat. Breaking/connecting the circuit all the time.

Sent from my iPhone using Tapatalk whilst in a taxi rank

[GaSelle]

I tried this once in my Octavia. That was due to wrong coding of the towbar electronics (another reason to use OEM!).

[BlackCat3000]

All working again.

I'd left the headlight switch on manual when fiddling around trying to get the warning display to sort itself out.

Set it back to Auto and the coming home / leaving home is working normally again.