Help needed desyphering error code

[toff]

Hi,

Since the very cold weather started, I occasionally get a

BRAKES
(!)

warning appearing on the DIS (between the speed & revs counter) just when I start the car (it goes off after a few seconds).

I thought it might be to do with a brake pad wear sensor being damaged by the ice (it was minus 3.5c on the night the warning first came on).

The thing is, the brake pad wear sensor warning looks different (and it's a yellow warning, not a red one).

Looking in the manual, it recommends that you check the brake fluid level - I have and the level is fine (it's closer to MAX than MIN, but still within the arrows).

I will get it booked into Audi ASAP but can anybody think what the problem might be? It's weird that it only appears every so often (not every time I start the car).

Any thoughts / help appreciated.
Al.

[kite]

This was a problem on the B6 diesels, thought they would of fixed it for the B7's.
I think the fix was a relay.
Crasher or A8tech posted up pics of the relay somwhere.

[toff]

Thanks for your reply.

Braking feels totally normal and the brake fluid level is normal (as I mentioned before) so I guess it makes sense that it's an electronic glitch.

The very cold weather seemed to be the trigger though. Is the relay in question under the bonnet or inside the car?

Cheers
Al.

[a8 tech]

There is no relay already fitted you retro fit a relay to reduce the voltage spike at cold crank to stop the false red warning symbol.Due to voltage drop at cold crank the brake level warning symbol comes on so first you need to make sure the battery is in good order then retro fit the relay and wiring loom.Attachment 4556
Speak to your local dealer and they will carry out the mod under warranty or if your warranty has expired the may do it as a goodwill gesture.

[toff]

There is no relay already fitted you retro fit a relay to reduce the voltage spike at cold crank to stop the false red warning symbol.Due to voltage drop at cold crank the brake level warning symbol comes on so first you need to make sure the battery is in good order then retro fit the relay and wiring loom.

Hi,

Thanks for this info. Audi have recently replaced my battery with a brand new one (and it's doing a great job of standing-up to the cold weather).

Is retro-fitting the relay & loom an Audi approved fix (i.e. will they do it for me under warranty?) or is it a DIY work-around because Audi don't recognise the problem?

Either way, I'd really appreciate it if you have a link of how to retro-fit this relay (I'm a competent splicer / solderer!) or part numbers if it's an offical retro-fit

Cheers
Al.

[toff]

Speak to your local dealer and they will carry out the mod under warranty or if your warranty has expired the may do it as a goodwill gesture.

Ah.. cheers, will do

[kite]

A8tech to the rescue again.

[toff]

A8tech to the rescue again.

Indeed.. it's people like A8 Tech, Crasher and all the other pro's that make the forum worth posting to! After all, A forum full of questions and no answers is useless!

By the way.. I've realised the "BRAKES" warning only come on when it's been very cold or when I haven't driven the cars for a few days.. so it's more than likely the voltage drop at cold crank.

I will let you all know what Audi say (fingers crossed I can get it booked in before Christmas!)

Al.

[Giles H]

This is an interesting post....my B7 Tdi does exactly the same thing when the temperature drops below about -3 deg. I spoke to Audi and they said it was a "frozen sensor"! Again, mine goes of in 2-3 mins, so I haven't worried about it, but I'll keep that tip in mind in case it gets worse.

Cheers for that!

[a8 tech]

Press the check button on the dash display when it happens and if the centre display shows low fluid then then the repair I have posted will resolve the fault.