Help please

[Mcgkerry]

I have an Audi A4 2.0 diesel on a 17 plate. 
had a new timing belt done. Car running perfect. However the following comes on every time. 
start/stop system fault: function unavailable

Driver system fault: contact Workshop. 
 

anyone have an ideas what could be causing it? Had an independent garrage plug it in to diagnose it. No fault codes at all. 

[cliffcoggin]

It could be the battery is on its way out. How old is it?

[Mcgkerry]

3 hours ago, cliffcoggin said:

It could be the battery is on its way out. How old is it?

The car is on a 17plate and I believe it’s the original battery

[Mcgkerry]

3 hours ago, cliffcoggin said:

It could be the battery is on its way out. How old is it?

Is there a way to test before purchasing a new one cause I believe I read that a new battery would have to be coded to the car?

[cliffcoggin]

There is no realistic way for the average user to test the battery. (A simple zero load voltage reading will tell you nothing about battery condition.) It needs to be tested under high load conditions and requires specialised equipment to do so. Many here will recommend Halfords for the job. Personally I will not as I believe them to be a bunch of clowns. The choice is yours.

At seven years old your battery is overdue for renewal, and yes it will need coding to the car.

[Magnet]

Hello Kerry,

If this car needs/now deserves a new battery - and to my mind it’s a question of confirming or otherwise whether it is a contributor to your issue - then I would only be ‘investing’ in a quality replacement. 
In case it helps, I don’t buy Halford’s batteries since they are generally nothing near competitively priced. 
Although my previous go-to make was Varta/Bosch, I am now favouring Exide and I have bought this brand from Tayna Batteries ( no connection with them and there are other suppliers). 
As Cliff points out- new one will need coding.

Kind regards,

Gareth. 

[Mcgkerry]

I will definitely be investing in a new battery. I can’t say for sure this one is 7 year old am just presuming. I have only owned the car 18months. Cost me a !Removed! fortune. As for the “warning messages” it doesn’t come on straight away. Takes from cold about 5/6 minutes before they come up. Once warm it’s a minute after driving. No power loss ect 

[Magnet]

If your battery is of unknown age (you have only owned the car for 18 months) then it may be an unnecessary expenditure to ‘invest’ in a new battery without first having its efficiency tested. Halfords shops will do that for you, and you will be doing your wallet a favour if you follow my earlier advice if (in caps) a new battery is required. 
My suggestion from the start has been to eliminate/incriminate the simple things first - in this case the battery, but this doesn’t automatically equate to renewing it without testing its efficiency.

Make of current battery? 
Kind regards,

Gareth. 

[Magnet]

Did you get any further with this Kerry?