Hi,

I have an 02 Octavia L & K and I have the following problems:

1. Whilst braking (with all lights switched off) my offside sidelight illuminates and the dash displays a "Lights failure" fault on the screen. It is intermittent and only happens say 50% of the time whilst braking.

2. When my lights are on (sidelights and dipped, haven't tried with dipped only) and I brake the dash displays a "Brake Light Failure" alarm (however the brake lights are working).

This all started last weekend when I applied the brakes and a "brake light failure" was displayed. The o/s brake light was indeed not working, so i replaced the bulb and all was fine after that. Since then I have had the above problems and the strange thing is that my cruise control wont work with my lights on any longer. Is that because the cruise control wont work when the system has a lights failure?

What software can I use to interrogate the system? With my audi I had a cable and used vagcom. Can that also be used with the Skoda? Also, what is the name of that application which lists the wiring diagrams for VAG vehicles?

Thanks for any help given.

Ross

Sound like a short is occurring in the rear lights. Probably with a negative feeding back into the rest of the lights.

Have you fitted the right bulb? Connector back on properly?

I would check the bulbs and all associated wiring.

Hope that helps.

Phil

Hi Phil.

Sounds like a valid suggestion. The first bulb, i just took the guy in the parts place's advice, but for the second bulb I got them to check their book and they said it was the right bulb.

I suppose I could of knocked the wiring though, i'll go out and make sure I haven't caused any damage. There's some other wiring going to what I assume is the lighting for the boot which is easily pulled whilst taking the bulbs out, so i'll check that first.

Good news is, that my VAG-COM cable fits the port in the car, so when i find my USB>COM Port converter I'll fire that up and see what it says..

Sound like a short is occurring in the rear lights. Probably with a negative feeding back into the rest of the lights.

Have you fitted the right bulb? Connector back on properly?

I would check the bulbs and all associated wiring.

Hope that helps.

Phil

Has the correct bulb been fitted?

I replaced the bulbs in my Octy Hatch and went for the normal 21/5 Watt type as fitted to most cars, but found that they did not fit correctly as the pins were in the wrong position. The bulb holder states 21/4 Watt and I went back to where I bought the first bulbs from and bought some of the correct wattage. These have the pins in the correct position and fitted without problem.

Sounds as if the wrong bulb has been fitted and it is bridging the two contacts in the bulb holder putting the front sidelight on when you brake.

If something was perminantly shorted, I'd expect the sidelight to come on every time I applied the brake, however it is intermittent.

I've just gone out and tightened all of the connectors, so i'll see how it goes. The bulbs I took out were 21/5 W, 12V and the pin patterns and wattage/voltage are identical on the new bulbs.

The only symbols that are different on the old and new bulbs are E1 (old) and E13 (new), but I don't know what those symbols indicate. I just started the car and it's not got the problem any more, but as I said before, it is intermittent. I'll give and update after i've driven it for longer.

Appreciate everyone's help.

Ross

It sounds like an earthing issue to me too. You've lots of advice on those already.

The other, rather off-the-wall sounding, possibility would actually be a problem with the brakelight switch (yes the one at the pedal). A search should tell you what to check to see if this is the case and/or the latest model.

check theres no water in the connectors further down the loom (left hand side of the boot under the CD autochanger if you have one) I found a small amount of water in mine last night (just a few drops in there but hte connectors have gone bad), and a search on here shows other people have experienced water here (a lot more than me in most cases) . I hoping cleaning them connects will sort out my 'works when it feels like it rear wiper' but basically all the rear electrics run through here so its worth a check (i only noticed on mine because I took the autochanger out).

Just for the benefit of anyone seeing this thread via the search function, I swapped the brake light bulb that I originally changed before the problem started (even though the bulb was illuminating) and it seems to have fixed the problem.

I suppose the bulb was faulty in some way. I'll update the thread if the problem comes back..