2017 A5 Sportback Stop/Start & Greyed Out A/C controls.

[Browny_37]

Hi all,

Back in a VAG car after 12 years away from the VAG platform and I've recently acquired a beautiful 2017 A5 Sportback with the 2.0TDI engine and DSG.

However I've some curiosities around potential faults? And how to approach this in the best manner.

So the AC part of the controls illuminate when the car is  in the "Ignition On/Engine Off" state before starting. However, upon start the AC Eco and AC parts become greyed out.  I suspect down to a lack of gas. (Yet to have this confirmed)

However in the menu that shows the effects on fuel consumption, the Air Conditioning is showing as being present in the menu and having an effect on consumption. Which I find odd given the AC is forced into the Off status?

No Fault Codes are present with a WIFI OBD2 Plugin and the Android app  "Car Scanner", however I have ordered VCDS.

 

So this is my first car with stop/start and it would appear that this is the cars original battery (Its a Varta 75AH 800CCA battery and it has has 04/17 stamped upon the battery post) I've have had very sparse and sporadic operation of the stop/start system and at present it has stopped functioning (symbol on dash to shows that its disabled whilst the vehicle is stationary with no error messages)

Battery was charged for 4hours yesterday using a CTEK Charger before I had to use the vehicle. Resting voltage of battery today is 12.35V at present and plan to continue charging today. 

 

Now I'm curious of how the systems work and if there's the possibility if they could affect one another? Any information would be greatly appreciated. 🙂

 

Edited Tuesday at 12:29 PM by Browny_37

[cliffcoggin]

A dying battery can indeed cause all the symptoms you describe. Get it tested if you want confirmation, but in your place I would not hesitate to replace an eight year old battery. Don't forget to get it coded to the car.

PS The volt meter readings tell you nothing about the internal condition of the battery.

[Browny_37]

14 hours ago, cliffcoggin said:

A dying battery can indeed cause all the symptoms you describe. Get it tested if you want confirmation, but in your place I would not hesitate to replace an eight year old battery. Don't forget to get it coded to the car.

PS The volt meter readings tell you nothing about the internal condition of the battery.

Good morning Cliff,

Thank you for taking the time to reply. Its greatly appreciated.

I think you're right regarding the battery being towards the end of its life.

Peculiar things are happening regarding the Stop/Start atm.

I decided to flick over to Dynamic and Sports mode yesterday and gave it a bit of a blast for a couple of minutes. Arrived home and comically as I pulled up the car decided to shut off.

Since then the car has been on charge again for several hours and the stop start hasn't functioned since 😅

Regarding battery sizes the car appears to have a 75AH onboard, but upon entering the details into the likes of GSF or Eurocarparts. Shows 3 options, Ranging between 95ah and 70ah.

Personally, I'd have thought such a car would have had a 95ah battery. But this is based on the pretence of coming from a 2.2D Mazda with such sized battery, I understand AGM is a different kettle of fish and that things aren't directly comparable hough. 

Not sure if to go for the bigger battery and hope the alternator keeps up or go for a battery of a similar size as now?

Do you have any thoughts on the battery size?

 

[cliffcoggin]

Fit whatever capacity is recommended by the manufacturer, but please ensure you install a good quality battery. Varta and Exide are two names that come to mind, though there are others whose names escape me. Avoid like the plague any cheapie from the internet or the likes of KwikFit.

[Browny_37]

1 hour ago, cliffcoggin said:

Fit whatever capacity is recommended by the manufacturer, but please ensure you install a good quality battery. Varta and Exide are two names that come to mind, though there are others whose names escape me. Avoid like the plague any cheapie from the internet or the likes of KwikFit.

Thanks Cliff.

So, according to this documentation. Audi recommends the fitment of a 93AH battery with 520A rating.

Somewhat of a jump from the VARTA 75AH 420A DIN that is in there at present. As there's quite a variance between online recommendations. I think I'll confirm with Audi for my specific Registration, before committing to purchasing a new unit. 🙂

Edited Wednesday at 10:56 AM by Browny_37

[Browny_37]

So as to assist other users regarding a battery. I've found the following Article regarding battery sizes.

https://www.vwvortex.com/threads/speaking-of-batteries-a-brief-review-of-etka-vag-part-numbers-and-pr-codes.9490580/

My battery in my service schedule is referred to as J1N. So 75AH 420DIN is in fact the correct battery for the car.

Hope this helps others.

Edited Wednesday at 11:53 AM by Browny_37
Typo

[Magnet]

Thanks Dan,

Well worth tapping your registration into Tayna’s website and asking them for recommendations and a quote for Exide. They will probably try to push you towards their ‘own brand’ Enduroline? , but if you stick with the correct Exide, you won’t go far wrong. 
Kind regards,

Gareth.