brake lights dash warning light on

Graze

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Be really grateful if anyone can help me out here. I've had this problem for ages - the brake lights warning light on the dash is permanently on although occasionally it goes off for a few seconds - then there's 'OK' then there's a beep and the warning light comes on again. I've changed the brake light bulbs, cleaned the contacts, checked and cleaned the fuse and swopped with another, tried disconnecting and reconnecting the battery after waiting ten minutes and ten hours - all the brake lights including the top third light work normally - still the problem continues. All other ECU functions are fault free. Is the ECU at fault do you think? Thanks in advance for any suggestions.
 
MINE DOES EXACTLY THE SAME, ITS THE ABS RELUCTOR RING ON THE BACK OF THE REAR DISKS. IT KEEPS FALLING OFF THE BACK OF THE DISK FOR ME ANYWAY....
 
get vagcom on it and see what codes are being thrown up.

Assume the brakes work ok ? fluid level good ? etc?
 
If it was this ABS thingy wouldn't the ABS light be on or the brake pad warning light be on? This is only the brake light bulb warning light that comes on. No other warning light ever comes on but the interesting thing is that since I had all the discs and pads changed and 2 lcd bulbs on the third light replaced I get the warning light on all the time except for an occasional 'OK' flash followed immediately by the beep and then the warning light on again. Previously this flashing and beeping would happen a lot but sometimes I would go for weeks with 'OK' and no warning light, then suddenly there'd be a beep and warning light and then after a mile OK then after another mile beep and warning light. Sorry to post so long here but trying to give as much info as poss. Did take it to an Audi specialist and the computer showed up brake light switch. Changed that but no success. Took it to another Audi specialist who detected nothing and said I must need a new ECU. I don't really believe that. Any more thoughts very much appreciated.
 
have you got the correct bulbs fitted ?
checked the earths / connections etc?

can you be a bit clearer about when this started and how new brakes / bulbs affected it?
 
Did you fit LED bulbs? As these can throw up errors because they draw so little current the ECU thinks they are blown.
 
Hi there - first query, I thought I must have the correct bulbs as I asked for brake light double filament ones. Will check again with Audi. Before the brakes were done sometimes I would go for 2 or three weeks with no warning light. Then suddenly there would be a beep, a warning light and the light would stay on for maybe 20 minutes, then it would go out and OK would appear. Sometimes OK would remain, other times another beep and warning light and the process repeated again and again. Then for no apparent reason OK would come on and I would have another couple of weeks free from beeping and the warning light.After the brakes were done basically the warning light is on all the time. As far as the connections go I have taken the bulbs out of the sockets and cleaned and sanded the contacts for the brake lights. 2nd query. New LED's from Audi specific to model. Thanks again!
 
I have access to VAG-COM if you want me to scan your car. I see your from Inverness, I am from Greenock so quite a distance there.

Are you going to any of the Scottish meets soon? As i could scan it then for you.
 
have you had the plugs off the rear light units, i had something similar on the 20v quattro i had a few years back that turned out to be corrosion on the plug due to water getting in there. i don't think the third light has anything to do with it, as far as i know it's not checked by the autocheck system.

do you have to press your brake pedal to get the "ok" message before you drive off or does it cancel itself automatically. on some of the earlier systems you had to press the pedal first, later ones changed because of european regs on brake light testing. if it's the earlier type i think they might be right about the brake pedal switch as i believe there could be 2 in there. i'll check my wiring diagrams after tea and see what i can find.
 
there's a control module for the rear lights under the drivers side lower panel. it's mounted on the relay carrier plate. not sure how it works but the drawings suggest it's in positions 4 and 5 on the 13 position relay carrier. there's a red/black wire coming from the brake light switch to the module your looking for. might be worth swapping that out.