Audi S4 B9 won't engage in gears from P

[atiqmughal]

Hi All, can someone please help me to resolve a puzzle i am stuck in. Car is Audi S4 B9, starts fine, it is damaged front end- offside. wiring looms looks fine. battery was dying, changed and coded. I am seeing issues with engaging into Gears. as soon as try to engage into gears, engine cut off, any advice on it?  Thank you in advance

 

[Mango Madness]

Evening, newbie here. 
If l give you a nudge in the right direction with yours maybe you can my car to start in return. 

I’ll be crying into a post about that later 😂 

Looks to me like you’ve got a serious comms issue across the Canbus system (U112100 Databus missing message)

I’d say there’s some wiring damage you can’t see..
 

[atiqmughal]

Hi thanks for your reply. I have checked the wiring and don't seems to find any broken wires, the only damage wire was ambient temperature sensor and I have replaced that sensor.

[cliffcoggin]

The wiring damage may not be visible externally. You could have: a break in a conductor inside intact insulation, a poor contact in one of the connectors, a short circuit inside one the components, or possibly other faults I have not thought of.

[Mango Madness]

It just feels electrical because of inability to communicate. Perhaps a h/s gateway module.
How is your battery? 

If that’s dying it could be strong enough to start and idle but drop out when you put the load into the engine. 
You can get a boggo multimeter for £6. Cheap way to eliminate one problem straightaway and you can do a quick continuity test on all the plug connectors too. Won’t take long..