A6 C6 Avant '07 2.0 TDI - hazard lights switch on and flat battery

[greg1983]

Hi,

I have an Audi A6 C6 Avant '07 2.0 TDI and have a problem...

Illumination of hazard lights stays on when car is locked - after approx. 48hrs battery is flat. I have already had diagnostics done in a local garage but it does seem that they were not any good, as could not find anything and returned car as non-fixable...

In one week time have an appointmet in main dealer workshop but am a bit scared about their labour charges (£105 per hour!!!), so try to figure it out by myself...

Currently I disconnect every day fuse in slot 32 on driver's side (30amps - smart power output module), which is responsible for hazard light swith illumination, horn, washer jets and footwell lights and connect it back every morning and everything works fine.

Is it possible that just hazard light switch is faulty or it just indicates any other problem?
Do any of you know how to replace it in this model? Pictures would be very helpfull...

Car was checked and there is no evidence of any water leak, etc. and scan was done to check all modules and they work fine.

Many thanks for you help.

Greg

 

[singhl]

Most likey a faulty indicator/hazard light relay, sorry cannot tell you where it is, but try VagCat boards (Powered by Invision Power Board), and goto the catalogue, select your model, and look under electrical and find the relay, or try an audi parts dept in person, they have diagrams and can get part and show you where it is.......

 

[greg1983]

Have you (or someone you know) had this situation before - flat battery because of the faulty relay in this switch?

It is really frustrating, as everything in this car works as it should...

Also I couldn't find hazard light swith in the catalog provided on this web site as I have C6 model and they sell parts for cars manufactured up untill 2005, which is C5 model...or I am not checking it properly?

It is a good sugestion to check audi parts dept, but because I haven't got any instructions how to replace it, I might give them to do it...and pay a massive bill for it

 

[singhl]

Get the part number from audi and where it is, you can then buy from anywhere like euro car parts or gsf.....

This is a common fault on volksvagan audi cars, any garage will be able to fit it, pull out the okd on and replace with new.....

 

[greg1983]

I have just spoken with Audi garage and was told that the battery I have fitted in my car currently doesn't match manufacture's spec (I have 75Ah, when it should be 110Ah battery with 520A) and every battery replacement shall to be done in authorized garage, as power management system has to be set up to recognize new battery.

It seems that the dealer I bought this car from replaced the old battery (maybe it went flat, so thought that it will be a good idea to replace it with a new one) but didn't know about consequences and requirement of re-setting.

Illuminated hazard light switch can still be faulty(?), but as a first thing I will buy bigger battery and have Audi to re-set power management system. Apparantly if you won't do it, alternator won't charge it properly and some systems won't switch off even when car is locked - I was told by their technician. I think it is a bit cheeky, as I mentioned above - by pulling out a fuse in slot 32 from driver's side stopped energy drain in my car.

I will let you know later whether 110Ah battery and re-setting of power management system were needed in my case.

If not, I will be lighter for about £200 and still with the same problem!

Thanks,
Greg

 

[singhl]

Audi are correct - the battery needs to be coded in the battery manager unit of the car, but if you get a new bigger battery and do not fix the hazzard light problem, the bigger battery will go flat as well - this is not good for a battery, first fix the hazzard light problem, and then the battery.

 

[greg1983]

Yesterdat Audi checked my car and did not find anything... Battery, MMI, charging system, all modules, ect. are working fine. The only funny bit about the whole story is that I had to jump start the car to bring it to their garage and next day the car started without any problems.

I asked them to keep the car for a few days on their parking and check every morning whether it will start as easily as on the first day...

They even did not look at the battery itself, but onyl did some checks using computer... It seemed pretty weird fro me, as a few days earlier they told me that I need to have an original Audi (Varta) battery...

I will see this afternoon whether the car started or not and will let you know.

 

[greg1983]

£301.99 later my car has a brand new battery fitted plus it had battery manager re-set and power management system was set-up to know what battery is fitted.

Audi have beed testing my car for 2.5 days and are confident that there are no other issues. Illumination of hazard light switch and the switch itself work fine...

Hope that all what was said above will help somebody and save a lot of precious time and money!!!

Cheers,
Greg