Problem Starting (Keyless)

[pnjriches]

My 2011 Audi A8 has an issue when starting. It was working as it's supposed to, foot on the brake, press the button and then Pesto it starts. Then it started playing up. Initially, sometimes when I would put my foot on the brake and press start it would start but I would get an error warning that the start/stop was not working. This tended to happen after there had been rain. Now it is a problem all the time. If I press the brake, then press start once the ignition comes on but it doesn't start. If I press the button a second time (with foot on brake) it starts but with the warning that the start/stop isn't working. If I press it once (foot on or off the brake) then with foot off (if it was on) press it a second time to turn the ignition off, then foot on brake, press the button, it starts and the start/stop is there. Go figure.

 

Anybody got any ideas? I talked to the garage I use but they had no idea.

[Steve Q]

Hi Peter sorry to hear your having issues. The first thing Id change Is the key battery, but I'm assuming you've already done this? 

Also have you had an auto electrician run a diagnostic test on the car to see what fault codes are coming up? If.not.it definitely will.be worth doing as it'll help narrow down your search for the faulty component. 

I'm wondering if the fault can be traced to a dodgy starter button? It's not unheard of for them to go wrong. 

Sorry I can't help.more. 

Cheers

Steve 

 

[pnjriches]

Thanks for your suggestions, tried them all and others. The auto electrician I had look at it told me there was not a fault code coming up. Like I said, it's a strange one.

[Steve Q]

Hmm, I'll have think. Intermittent faults are the worst though! 

[pnjriches]

Thanks, but interestingly, it's not intermittent now. It's predictable. the same thing happens each time. It was intermittent at first. When I say that I mean it didn't happen all the time but seemed to occur after there had been rain. Once things dried up, the issue went away and it worked normally. But like I say, the issue is there all the time now.

Previously I had a A8 D3 that had a problem with the stability control light coming on after it had been running a while. Also the heated rear screen then stopped working. The main dealer could not solve the problem. The garage I now use sorted it out. It was the alternator affecting the battery computer which in turn caused the issues with the stability control and the heated rear screen, go figure. The same garage has looked at this problem and as yet do not have an answer for me. Hence the reason for reaching out.

 

Thanks again

 

[Magnet]

Hello Peter,

I could be barking up wrong trees here but with all electrical faults, I always first eliminate the battery by getting it tested under load. Appreciating this vehicle is only  6 years old, you would not expect the (original?) battery to be suspect, but I am unsure of the life expectancy of batteries subjected to the stop start system. Apologies if your garage has (definitely) elininated this possibility.

If you do indeed eliminate the battery, it might well be worth looking at the brake (light) switch, which I believe plays an important part in the operation of the stop/start system. 

Kind regards,

Gareth.

[pnjriches]

Thanks for giving this some thought. I have considered this area as well but your comments cause me to give it some more thought.

The car was serviced just last month and that was when I had the garage check it out, by that I mean I had this issue and told them about it and asked them to look into it/check it out. Checking the battery is part of the service but I will check back with the garage and ask specifically that the battery check was done and what is was. Also, reading some other forums, battery issues can cause problems with the BEM (Battery Energy Management I think) which can manifest itself as many different things. I think I will put the battery on a charger and make sure it is absolutely fully charged then see how it goes before going to the expense of a new Battery (they aren't cheap).

I haven't yet, but I will check the brake light as you suggest.

 

Again, thanks for taking the time and effort to offer your thoughts.

[Magnet]

Hello Peter,

You are very welcome. 

Battery and should be checked at service?? Um - in reality, only if there were obvious reasons at the time to suspect it wasn't serviceable. Are you sure they alway check your tyre pressures for example? - they should but......! 

If it were mine, I would simply be doing what you suggest and charging the battery overnight and taking it to either a good auto electrician or Halfords an getting the battery efficiency checked. If it is found to be sub standard then if you respect  your wallet, you may be wise to check alternative prices to Halfords. I have used Battety Megastore at Tewskesbury (no connection and there are others -e.g.Tayna etc.) , but I always buy batteries which have at least a 4 year guarantee - Varta amongst others. I think you will find prices are reasonable.

Brake light switch. It may not be as simple as checking if the brake lights work and assuming if they do, that the switch is 100% serviceable. Anyway Peter, Battety check first I think.

Kind regards,

Gareth.

[pnjriches]

For anyone following this post.

I think I found and sorted the problem. It appears to have been water ingress from the top of the windscreen. I started to notice a few drops of water on the drivers seat. I noticed the top of the interior trim in front of the sun visor, drivers side, was wet. At the same time I got another problem, this time with the power steering. It became very heavy as if not working at all, then later it was just heavy. Anyway, I eventually sealed the windscreen using some flowable silicone and as the interior has dried out, so the issue with the power steering disappeared and the start/stop went back to being intermittent then disappearing completely.

I have since learned that windscreen leaks are common on the A8 (anecdotally)

Thanks to all those that tried to help

Peter