Red Brake Warning!

[stevehall]

I have a problem with my 2.0T FSI, When I come out in the morning or after a full day in the office and I start the car sometimes I get the 3 beeps and the RED Brakes! warning flash up for a few moments? Put the car into drive and move off and it clears its self? and the brakes seem to work when I am driving?

I guess that if it was a true major fault it would be on all the time, and not stop as soon as I move off?

It only seems to do it in the cold as well, last winter it did it once or twice, I mentioned this when it went in for a service and they say they topped up the fluid and it should all be ok, and then it did stop but it also started to get warmer?

I have done a few Google hunts on this and some people say there is a known fault out there and they have had relays changed? Anyone know more on this? Also some people have said its down to the battery being on its last legs? It’s a 05 car with 90k on it (I have done 60k in the past 12 months) and as far as I know it is still the same battery? But it seems to start the car find and not have any problems keeping the lights bright when engine is not running?

 

[hilly]

mine does the same like you say when the car is cold i sometimes get the light but then it goes out after about 2 seconds!not ad it for a few days now!dont think it will be your battery it would towing to start.

 

[rowdyboy]

I might be stating the obvious here but have you actually had the brake pads and sensors checked??? You havnt mentioned that you have. It would be the first thing I would check, you may have a chaffed sensor wire letting moisture in or your pads are worn unevenly.

 

[stevehall]

Well i told Audi about it last winter, and they said they topped up the fluid and it should be ok, so i guess they would have checked everything over?

Also when it had its service in summer just gone (if you can call it a summer) they said it needed new disks and pads and i did not have the time to shop about so they did it all for me then? So would have hoped they should have found any faults on brake system?

 

[hilly]

if it was the pads it would display a different warning light.it would be the round amber light.

 

[gjwell]

I had the same with mine last year. My friend (who works for Audi) topped up the brake fluid and the problem when away. I would check the brake fluid level, and suspect a faulty fluid level sensor if it still does it. May be error codes on VAG COM could be of assistance?

 

[jwhat]

If your brake fluid is ok, then I think it's probably the battery being low and needing replacement soon, causing some sort of spike that triggers the warning. Audi Have a service bulletin for this that involves installing a relay into one of the circuits. It happens me when I start the car on a cold day too.

 

[Mike B]

There is a similar problem on B6s- see on theforum .Could be the battery cable pressing on the sensor under the reservoir .Move it away alittle and it should help and also keep the battery charged up.This worked on mine after i had the res changed which made no diff.

 

[Skip]

Its a known problem with the self test function of the brake system when the car starts up, so my local audi dealer told me. I had the same problem which was corrected under warranty.

 

[NHN]

So an updated firmware would be needed then to correct this issue on the module that runs the tests.

 

[stevehall]

Its strange, only when very cold...

If i start the car when cold i sometimes see the handbrake light flash for a few seconds, and if i put the car into D while its flashing i get the red brake warning, if i wait for the light to stop flashing before putting it into d its all ok

 

[stealth64]

ok dont rain bullets on me but...

Its not the warning that comes on and bleeps when the outside temp is below 5 degrees is it?

 

[stevehall]

ok dont rain bullets on me but...

Its not the warning that comes on and bleeps when the outside temp is below 5 degrees is it?

No, Its deffo brakes as it says BRAKES!.

I dont get a beep when its below 5, just a nice little snow flake.

 

[stevehall]

I think this has got to be my battery, as i have noticed now that when i press my windows up the lights dim etc.

Anyone know of a way to test the battery?

 

[pjmspeedy]

Anyone know of a way to test the battery?

Stick a multimeter on it.

 

[stevehall]

Whats the best way to check its OK with load, as it reads 12V ish most when everything off.

If i put on main beam for example how much should it drop?

 

[pjmspeedy]

If you check with everything off it should measure,
12.6 = fully charged.
12.4 = means half charged
12.2 = flat, if it's below this then it's kaput!

If you check with the engine running it should be around 13.9-14.0 ish

If you then turn on lights, rear heated window etc you should see the voltage drop but after 30 secs or so it should start to creap back up to roughly what it was before. This then tells you that the charging system is in fully working order.

 

[Mike B]

Moving the battery wire from the sensor under the brake res and keeping the battery fully charged continues to work on mine.Still not sure why?

 

[stevehall]

Well parked my car up at work this morning, and went out just now with a meter, and its reading 12.1V

Also had lots of corrosion (while powder substance) on the + terminal.

So is it time for a new battery?

 

[pjmspeedy]

Well parked my car up at work this morning, and went out just now with a meter, and its reading 12.1V

Also had lots of corrosion (while powder substance) on the + terminal.

So is it time for a new battery?

I would say yes but if you want to try and rescue it then leave it on charge for a fair amount of time.

Then measure it again over the weekend. If it has dropped again then you do need a new one for sure.

 

[stevehall]

I do lots of miles in my car, Yesterday was over 300, and driving for 8 hours - so i would have thought it was fully charged from that?

I think i till take the battery out tonight, and clean all the contacts up and see how that goes.

 

[pjmspeedy]

Good luck in taking it out as it's a bitch of a job

 

[stevehall]

Might save it for the weekend then, as dont fancy doing it in the cold and dark.

Have to be the pub tonight then!

 

[PetrolDave]

so i would have thought it was fully charged from that?

When a battery is too old to hold charge it doesn't matter how much charge you throw at it, it still ain't gonna hold it!

 

[TorqueTerrorist]

Good luck in taking it out as it's a bitch of a job

Yes, yes it is!!

 

[stevehall]

Went out yesterday to take a look.. how do you remove the battery? i could not see in the snow..

I got a reading off it again over the weekend and it was 11.2V - so defo on its way out!

 

[PetrolDave]

it was 11.2V - so defo on its way out!

That's not just on it's way out - that's cream crackered!

 

[stevehall]

I just hope thats why i get the brakes warning!

And hope the battery will last till after new year!