Car want start after battery went flat

[Thomasmann]

Hello so basically I have Audi q7 car battery has been fine but car been sat for few weeks so had jump car off with my jump starter started fine any way 4 days later went move the car was flat so try jump of again but wouldn't jump off so I left the battery on charge over night and it taken a charge fine put all seat back in after charge and car seemed be ok everything working ie light doors Santa screen and clocks radio ...... then went turn the key to start and nothing no clicking or out just nothing it's like it's in gear but its not in gear on box it's in park and I've tried it in N nutual too still want fire up no engine cracking nothing but every thing else works any ideas please as getting !Removed! off with it now and dosent help the cars up for sale to cheers for any advice guys and girls and car is Audi Q7 3ltr Tdi 2007 cheers Tom 

[Magnet]

Hello Thomas,

Did you try the headlights after charging the battery? If so were they bright? If yes, did you try to start the car with the lights on, and if so, did they go out/dim?

My next move would be to again charge the battery overnight - or preferably for 24 hours- and then getting the battery’s efficiency checked (Halfords, for example, can do that). Whether you buy a new battery from them if it does prove to be substandard would be your choice. 

Kind regards,

Gareth.

[Thomasmann]

Hello I'm not to sure as was day time so not sure 

[Thomasmann]

[Thomasmann]

Just do scan on my snap on solus pro and engine management brings up this code cheers 

[Magnet]

That’s called sophistication Thomas! 

 I’m from the school of simple things first, and in my book, that would be assessing the efficiency of the battery - then move on to the more complicated aspects, once you have eliminated that. 

Kind regards,

Gareth. 

p.s. Having the headlights on is fairly simple way of gauging the battery’s ability to act under high current demands. If the lights dim considerably on attempts to start then all is not well. 

[Bigdave1230]

The fault code you have relates to the transmission control module 🤔 which I think is under the passenger seat in the battery area. I’d check all connections and wires there first to make sure you’ve not caught something whilst sorting the battery. It looks like a black module and isn’t very big. Without it connected the car doesn’t know it’s in park and goes into a kind of limp mode where it keeps the abs light on all the time. Check on eBay for a picture of what your looking for.

[Thomasmann]

Is this it cheers 

[Bigdave1230]

Not sure it should have one big multi pin connector on one side. It looks like it but I don’t think there’s an earth connection on the top

[Bigdave1230]

I think that’s the battery control regulator